LXXII International conference "Nucleus-2022: Fundamental problems and applications"

11 Jul 2022, 09:00 → 16 Jul 2022, 17:00 Europe/Moscow

[Русская версия]

Nucleus-2022 is a part of a series of annual conferences held since 1950 by major nuclear research centers of the Russian Federation and CIS states. This time the conference will be hosted by Moscow State University and will bring together experts from different countries in the field of fundamental and applied nuclear science.

Conference topics include:

• Nuclear structure: theory and experiment
• Experimental and theoretical studies of nuclear reactions
• Intermediate and high energies, heavy ion collisions
• Neutrino physics and nuclear astrophysics
• Design and development of charged particle accelerators and ionizing radiation sources
• Applications of nuclear methods in science and technology
• Synchrotron and neutron radiation sources and their use in scientific and applied fields
• Nuclear technology and methods in medicine, radioecology.

The participants will be able to present and discuss their talks either in person or online.

Important dates
Abstract submission deadline:  April 1, 2022  Extended to April 15, 2022
Program committee decision communicated to authors of abstracts: mid-May, 2022
Conference fee payment deadline:  June 1, 2022   Extended to June 20, 2022  Extended to June 30, 2022

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NUCLEUS-2022 will open on July 11, 2022 at 10:00 AM in the conference hall of the Shuvalov building of the Lomonosov Moscow State University (for directions see link to Google Maps below).

Registration of participants starts at 9:00 AM.

Please refer to the leaflet for more detailed description of location of conference sessions.

Watch live video stream of the first plenary session on YouTube channel of SINP MSU.

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Our sponsors

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nucleus-2022-abstract-template.docx

nucleus-2022-book-of-abstracts-www.pdf

nucleus-2022-leaflet.pdf

Nucleus-2022 official poster.pdf

nucleus2022-program-with-rooms.pdf

Monday, 11 July

09:15 → 10:00 Registration

10:00 → 11:40 Plenary session: Opening

Convener: Aleksandr Chernyaev (Lomonosov Moscow State University, Russia)

10:00 Opening

10:30 Limits of nuclear masses and elements

Speaker: Prof. Yu.Ts. Oganessian

11:05 NUCLEAR PHYSICS FOR THE WORLD ECONOMY

This paper reviews the achievements of nuclear physics for various fields of knowledge and unique technologies in the sectors of the world economy. It is difficult to imagine modern society without the achievements of nuclear physics. It is also one of the driving forces for the development of our civilization.
Counting back to the first nuclear reaction carried out, which is more than a hundred years old, we can conditionally distinguish three stages in the development of nuclear physics. The first one ranges (1919 - ~1954) from the first nuclear reaction to the creation of nuclear weapons and energy; the second part goes from the emergence of elementary particle physics to its intensive application in practical technologies (~1950 - ~2000); the third stage is the dominant development of applied nuclear physics research and technologies (since ~2000).
The impressive achievements of nuclear physics include the creation of nuclear energy, nuclear medicine and radiation therapy, nuclear beam diagnostics, the widest use of nuclear physics facilities - accelerators in industry and agriculture, the construction of the first all-European TOKOMAK, unique experiments on neutrino coupling, and many others.
The nuclear physics development leaves a firm confidence that the rate of nuclear technologies and methods invasion into our life will only increase.

1. Radiacionnye tekhnologii. Nauka. Narodnoe hozyajstvo. Medicina. Izdatel'stvo Moskovskogo universiteta Moskva, ISBN 978-5-19-011409-6, 231 s., 2019.
2. Belousov A.V., Varzar S.M., Zheltonozhskaya M.V., Lykova E.N. Chernyaev. A.P. Perspektivy razvitiya radiacionnyh tekhnologij v Rossii. Yadernaya fizika, tom 82, № 5, s. 425-439 DOI, 2019

Speakers: Prof. Alexander Chernyaev (Lomonosov Moscow State University) , Ekaterina Lykova, Polina Borschegovskaya (Physics Department, M.V. Lomonosov Moscow State University, Moscow, Russia; Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University, Moscow, Russia) , Marina Zheltonozhskaya (Lomonosov Moscow State University)

11:40 → 12:00 Coffee-break

12:00 → 13:45 Plenary session

12:00 NICA Megascience Project at JINR: Status and Plans

The Nuclotron-based Ion Collider fAcility (NICA) is the flagship project at the Joint Institute Nuclear Research (Dubna, Russia). Two goals of the project — experimental studies of dense nuclear (baryonic) matter and particle spin physics — are combined in the project on the basis of a common experimental method: the investigation of collisions of nuclei at relativistic energies. The project is under active stage-by-stage realization. The report describes in detail the NICA scheme, the technical solutions being used and status of the project development.
An achievement of design luminosity requires overcoming many technological and beam physics problems, which are described in this report.

Speaker: Prof. Igor Meshkov (JINR Dubna Russia)

NICA Project Abstract.docx

12:35 Deep-underwater neutrino telescope Baikal-GVD

The Baikal-GVD neutrino telescope is a water Cherenkov detector with a volume of 1 cubic kilometer constructed in Lake Baikal for the study of natural fluxes of high-energy neutrinos. Since April 2022, the telescope has been operating in a configuration with 10 clusters consisting of 8 strings of deep-sea optical modules (OM) each. The total number of OM, based on the photomultipliers R7081-100 with a photocathode with a diameter of 10 inches, is 2916. Each cluster is an autonomous independent neutrino telescope, which makes it possible to conduct physical research at all stages of the construction of the Baikal-GVD telescope. Currently Baikal-GVD is the largest neutrino telescope in the Northern Hemisphere. When analyzing the data obtained during the operation of the detector in the configurations of 2019, 2020 and 2021, the first candidates for events initiated by high-energy neutrinos of astrophysical nature, were identified. The Baikal-GVD detector is included in the international multichannel notification systems, in order to search for and further study transient astrophysical sources by methods of multi-wavelenght and multi-messenger astronomy.

Speaker: Prof. Grigory Domogatsky (INR RAS)

13:10 PECULIARITIES OF STRUCTURE OF WEAKLY BOUND LITHIUM NUCLEI (A = 6–11) AND NUCLEAR REACTION MECHANISMS AT LOW ENERGIES

Review talk considers present-day status of experimental and theoretical results on angular distributions and total cross sections of reactions with light weakly bound lithium nuclei (6–11Li). Peculiarities of stucture of light weakly bound lithium nuclei (6–11Li), their effect on mechanisms of nuclear reactions are discussed. The works from recent (2017–2022) years [1–5] are also analyzed in the review.

Speaker: Prof. Kairat Kuterbekov (L.N.Gumilyov Eurasian National University, Faculty of Physics and Technical Sciences)

nucleus-2022-abstract-kuterbekov.docx

13:45 → 15:10 Lunch

15:10 → 16:55 Plenary session

Convener: Eduard Boos

15:10 Some highlights of research on heavy ion collisions by ALICE at LHC

...

Speaker: Grigory Feofilov (Saint-Petersburg State University)

ALICE-talk-NUCLEUS-2022-version-11072022.pdf

ALICE-talk-NUCLEUS-2022-version-11072022.pptx

nucleus-2022-abstract-ALICE.docx

15:45 Geant4 status and applications: from HEP to nuclear medicine

...

Speaker: Prof. Vladimir Ivantchenko (Тomsk State University)

16:20 Structure of heavy nuclei and nucleon-nucleon interaction

The report considers:
- phenomenological approaches to finding effective nucleon-nucleon
forces for
calculations of nuclear structure;
- shell model calculations in large configuration spaces;
- calculations of nuclei structure based on free
nucleon-nucleon potential;
- Energy Density Functional approach;
- effective field theory for nucleon-nucleon
interactions in the cores.

Speaker: Rostislav Jolos

nucleus-2022-abstract-jolos.docx

16:55 → 17:15 Coffee-break

17:15 → 19:00 Plenary session

17:15 Nuclear Structure across the energy scales from microscopic effective theories

The microscopic theory of atomic nuclei now spans energy scales from kilo-electron-volts to giga-electron-volts. The leading degrees of freedom for prominent experimental phenomena range from clusters or collective modes of nucleons to quarks and gluons. Many profound questions can be raised. Is there harmony across scales? Are there emergent phenomena at one scale that trace their origins to a higher energy scale? Are there theoretical tools that are useful at more than one scale? Can one establish that theory retains predictive power?
At the highest energy scales accessible to current and planned laboratory experiments, there is widespread agreement that atomic nuclei should be well-described by the Standard Model of Elementary Particles. How can we achieve this? I will present Basis Light Front Quantization1 as a relativistic Hamiltonian approach for quarks and gluons that is complementary to Lattice QCD and capable of describing nuclear phenomena using supercomputer simulations. The first goal of successfully describing mesons and nucleons is progressing rapidly and phenomena such as chiral symmetry breaking are becoming better understood2. Near-term goals include the properties of exotic baryonic systems and properties of the pion-nucleon and nucleon-nucleon interactions.
At the lower energy scales, Chiral Effective Field Theory (χEFT)3,4 has emerged as the systematic and controllable embodiment of QCD below the chiral symmetry breaking scale. Can we discover collective nuclear phenomena emerging from treating all nucleons on an equal footing? I will present recent results from the ab initio No-Core Shell Model (NCSM)5 with χEFT interactions showing promising agreement between theory and experiment6 within well-quantified theoretical uncertainties. Exotic phenomena such as alpha clustering7 and predictions of a tetraneutron resonance8 serve as example highlights.

1. J.P. Vary, et al., “Hamiltonian light-front field theory in a basis function approach”,
   Phys. Rev. C 81, 035205 (2010)
2. Y. Li and J.P. Vary, “Light-front holography with chiral symmetry breaking,”
   Phys. Letts. B 825, 136860 (2022)
3. R. Machleidt and D.R. Entem, “Chiral effective field theory and nuclear forces,”
   Phys. Rep. 503, 1 (2011)
4. E. Epelbaum, H.-W. Hammer and Ulf.-G. Meißner, “Modern theory of nuclear forces,” Rev. Mod. Phys. 81, 1773 (2009).
5. B.R. Barrett, et al., “Ab Initio No Core Shell Model,” Prog. Part. Nucl. Phys. 69, 131 (2013)
6. P. Maris, et al., “Light nuclei with semilocal momentum-space regularized chiral interactions up to third order,” Phys. Rev. C 103, 054001 (2021)
7. T. Otsuka, et al., “Alpha-Clustering in Atomic Nuclei from First Principles with Statistical Learning and the Hoyle State Character,” Nature Communications 13:2234 (2022)
8. A.M. Shirokov, et al., “Prediction for a four-neutron resonance,”
   Phys. Rev. Letts. 117, 182502 (2016)

Speaker: James P. Vary

Nucleus-2022_v1.pdf

17:50 ANALYTIC CONTINUATION OF EXPERIMENTAL DATA ON SCATTERING AND REACTION PROCESSES AS A WAY TO OBTAIN INFORMATION ON CHARACTERISTICS OF BOUND NUCLEAR STATES

Asymptotic normalization coefficients (ANC) determine the asymptotic behavior of nuclear wave functions in binary channels at distances between fragments exceeding the radius of nuclear interaction (see the recent review paper [1] and references therein). ANCs are of particular importance for nuclear astrophysics. They determine the overall normalization of cross sections of radiative capture reactions at astrophysical energies [2]. In terms of ANCs, the cross sections of peripheral nuclear transfer reactions are parameterized. ANCs should be included in the number of important nuclear characteristics along with such quantities as binding energies, probabilities of electromagnetic transitions, etc.
Unlike binding energies, ANCs cannot be directly measured. In the present work, we discuss two ways to obtain information about ANCs by analytic continuation of experimental data. The first method is based on the analytic continuation of the experimental differential cross sections (DCS) of nuclear transfer reactions in the variable z = cos θ, where θ is the scattering angle in the center-of-mass system. The idea of the method goes back to the work of G.F. Chew [3], in which it was stated that the extrapolation in cos θ of the DCS of the elastic NN scattering to the pole corresponding to the exchanged virtual pion can be used to determine the pion-nucleon coupling constant. When applying this method, it is very important to take into account the Coulomb interaction in the initial, final and intermediate states [4].
The second approach uses the analytic continuation in energy of the partial-wave amplitudes of elastic scattering, determined from the phase-shift analysis of experimental data, to the pole point located in the nonphysical region of negative energies. In this way, ANCs were determined for a number of light nuclei. As an example, we present the recently obtained by us average values of the ANCs C(Jπ) for the virtual decay of the excited bound states of the 16O nucleus, which are important for nuclear astrophysics: 16O*(Jπ)→α+12C(g.s.). We got: C(0+) = 1.01·103 fm-1/2; C(3–) = 3.53·102 fm-1/2; C(2+) = 1.57·105 fm-1/2; C(1–) = 2.55·1014 fm-1/2.

1. A. M. Mukhamedzhanov and L. D. Blokhintsev, Eur. Phys. J. A 58, 29 (2022).
2. A. M. Mukhamedzhanov and N. K. Timofeyuk, Sov. J. Nucl. Phys. 51, 679 (1990).
3. G. F. Chew, Phys. Rev. 112, 1380 (1958).
4. L. D. Blokhintsev and D. A. Savin, Phys. At. Nucl., 85, 154 (2022).

Speaker: Leonid Blokhintsev (Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University)

abstract_Blokh-Savin_NUCLEUS-2022.docx

18:25 Двухкоординатные газоразрядные детекторы нейтронов на основе российской цифровой придетекторной и регистрирующей электроники.

Speaker: А.В. Пашков (ООО "Детектрон")

18:35 Доступная для заказов в 2022 году электроника для научного эксперимента и её развитие

Speaker: И.С. Бредихин (ООО "Гамматек")

19:15 → 21:00 Welcome party

Tuesday, 12 July

10:00 → 11:40 Applications of nuclear methods in science and technology

Convener: Nikolay Chechenin (Lomonosov Moscow State University)

10:00 Contacts for self-scanning SiC energyconverters in nano-microwatts range

The authors investigate the beta-electrons energy conversion into electrical energy inside 3C-SiC*/Si heterostructures doped with carbon-14 [1], which acts as an internal source of primary electrons spectrum and as the radioisotope nuclear energy accumulator. The question is raised in connection with the description of the endotaxy effectivness at the structural level, which means the growth of the doped single-crystal film inheriting the crystallographic orientation of the transformed Si-phase. The analysis of the technological aspects of the formation by endotaxy of high-temperature stable and radiation resistant β-SiC/Si heterostructure with respect to the concentration distribution of point defects of various nature, deep centers [2] and their probable association models with the participation of an impurity is the main way to increase the physical sensors reliability. The analysis of reversible association processes opens up ways to optimize the kinetics of diffusion mass transfer and microalloying during the phase transformation of silicon substrate into the silicon carbide film [3]. The dependences of the neutral defects concentrations on the factors of supersaturation of the gas phase by the conditional atomic concentration of carbon, on the concentration of impurities in the gas phase, as well as on their own defects of various nature, have the potential for the formation of deep levels in the forbidden zone and the potential for association [3]. The efficiency of the created structures depends on the combination of radionuclide activity and the formation of the contact area, which is confirmed by the beta spectrum research by the authors.
The dependence of the carrier generation efficiency on the activity or the introduced concentration of the radioisotope in the crystal lattice, taking into account the phase formation is evaluated. It is important to evaluate the possibility of structures metallization in order to collect nonequilibrium charge carriers taking into account changes in the work function. At this stage chips of structures with the size from 1x1 mm are used. At the same time, it is important to investigate the degree of influence of boundary effects. Research in the framework of this work also includes consideration of the band structures of the device, since there is an understanding of the alloying effect impurities with radionuclide on the position of energy levels in the band structure.

1. A. V. Gurskaya, M. V. Dolgopolov, V. I. Chepurnov, Physics of Particles and Nuclei. 48, 941 (2017).
2. A. V. Gurskaya etc. J. of Physics: Conf. Series. 1686, 012040 (2020).
3. V. I. Chepurnov Vestnik Samarskogo Gosudarstvennogo Universiteta. Estestvenno-Nauchnaya Seriya. 7(118), 145 (2014)

Speaker: Dr Mikhail DOLGOPOLOV (Samara University)

nucleus-2022-abstract-Dolgopolov.docx

nucleus-2022-Dolgopolov-Gurskaya —2.pdf

10:20 Flexible scenario for background suppression in heavy element research

New algorithms to operate with new analog spectrometer of the DGFRS2 installed at DC-280 cyclotron setup are presented. The main goal of application of these algorithms is to search an optimal time correlation recoil-alpha parameter directly during the acquisition C++ code execution. A new real-time flexible algorithm is presented in addition to the conventional ER-α one which is in use for a few years at the DGFRS1 setup installed at the U-400 FLNR cyclotron. Note that the spectrometer operates together with the 48×128 strip DSSD (Double Side Strip Detector; 48x226 mm$^2$) detector and low pressure pentane-filled gaseous detector (1.2 Torr; 80x230 mm$^2$) are presented schematically. First beam test results in $^{48}$Ca induced nuclear reactions are presented too.

Speaker: Yury Tsyganov (JINR)

Abstract.docx

10:40 LOOKING FOR AN ELECTRON BRIDGE IN 229mTh

The isomeric state 229mTh has the energy of 8.3(2) eV [1]. The small natural width and the location of the transition in the optical range give hope for the use of this state as an oscillator with a quality-factor several orders of magnitude higher than the Q-factor of the systems currently in operation.
Changes in the electron shell with changes in the degree of ionization, chemical environment, environmental parameters and the presence of external fields can have a significant impact on the probability of both discharge and settlement of the isomeric state through the mechanism of electronic bridges. Knowledge of the features of the decay of the isomer under the condition of the energy prohibition of direct electron emission will allow us to determine the optimal parameters of the feeding of the isomer using the electronic bridge mechanism. The “tuning" of the electron shell can increase the probability of isomer excitation by several orders of magnitude [2]. The probability of discharge through electronic states is a good indicator for such adjustment.
The existing limitation on the lifetime of the isomer in a singly-charged thorium-229 (T1/2<10ms [3]) ion allows us to hope for using the lifetime of the isomeric state as an indicator of the width of the electronic bridge.
The report presents the details of the preparation of an experiment to search for the decay of the isomeric state of thorium-229 through the mechanism of an electronic bridge. The method [4, 5] of formation of a beam of ions of the thorium isomer, the scheme of ion transport and preparation of a thin source and registration of conversion electrons will be considered.

1. B. Seiferle et al., Nature 573, 238 (2019).
2. F.F. Karpeshin, M.B. Trzhaskovskaya Nucl. Phys. A 1010 (2021) 122173
3. B. Seiferle, et al., Phys. Rev. Lett. 118, 042501 (2017)
4. V. Sonnenschein, et al., Eur. Phys. J. A, 2012, vol. 48, p. 52.
5. Y.I. Gusev, et al., Bull. Russ. Acad. Sci.: Phys., 2016, vol. 80, no.8, p. 875.

Speaker: Andrey Popov (PNPI)

nucleus-2022-abstract_22_02_2022.docx

11:00 CONJUGATE OBJECTS IN QUANTUM COMMUNICATION

CONJUGATE OBJECTS IN QUANTUM COMMUNICATION

A. S. Sitdikov1,2, A.S. Nikitin1
1 Kazan State Power Engineering University, Kazan, Russia;
2Kazan (Volga region) Federal University, Kazan, Russia
E-mail: airat_vm@rambler.ru

The basis of quantum communication is a set of methods for transfer of information encoded with the help of quantum states of elementary particles. The carrier of a unit of quantum information in this case is a qubit - a two-level quantum system (a photon with vertical and horisontal polarizations, an electron with two basic states, an ion of a hydrogen molecule H+2 with basic states of electron localization at the first or second proton, etc.). Nuclear objects - nucleons can also be considered as a qubit with two basic states in the isospin space.
In [1], we construct the algebraic model for the study of few-nucleon systems with non-abelian superselection rules, and in [2], this model was applied to describe the transfer of quantum information in the presence of constraints by superselection rules by isospin. Isospin is a non-abelian charge and it is convenient to describe such charges based on the framework symmetric tensor C-categories. In [2], it was shown that the transmitted number of classical messages encoded in qubits is equal to the number of coherent superselection sectors, taking into account their multiplicity. Within the framework of algebraic model, superselection sectors can be defined as a class of unitary equivalence of an irreducible endomorphism [ρ] (as an object of the C-category) of the algebra of observables of the system.
In the study of the quantum communication, as well as quantum cryptography, due to the compensating property, the conjugate charge also plays an important role. In this paper, a study is carried out of conjugate superselection sectors [ρ]* corresponding to a conjugate object (charge) of the category. It is shown that the constructed conjugate object satisfies the required conjugate equations. Classes of morphisms intertwining super-selection sectors and certain functions over these morphisms are studied, which allow us to identify the properties of the conjugate charge generating certain superselection rules.

Speaker: Айрат Ситдиков (Россия)

nucleus-2022-abstract-template angl.docx

11:20 Perspectives of inorganic scintillator GAGG application for precision electromagnetic calorimetry

Scintillation crystals made of a new promising material Gd₃Al₂Ga₃O₁₂ (GAGG) are considered because of their high radiation resistance, density and light yield [1, 2].These crystals can be used in addition to lead tungstate (PbWO4) crystals for development of a new generation electromagnetic calorimeter with good spatial and energy resolutions in a wide energy range. PbWO4 crystals enable accurate detection of high energy photons, while the addition of GAGG crystals makes it possible to precisely measure photon energies down to a few MeV.
Different options of composite electromagnetic calorimeter based on PWO and GAGG crystals are considered to optimise spatial and energy resolutions in a wide energy range (from 1 MeV to 100 GeV). Optimisation is based on GEANT4 simulations with accounting of light collection using different photodetectors and a noise of electronics. The simulations are verified using measurements of GAGG samples obtained with radioactive sources and test beam measurements of PbWO4 based Photon Spectrometer of the ALICE experiment at CERN [3].
1. K. Kamada, T. Yanagida [et al.], IEEE trans. on nuclear science 59(5):2112-2115 (2012)
2. Y. Zhu, S.Qian [et al.], Optical Materials 105, 109964 (2020)
3. D.V. Aleksandrov [et al.], Nucl. Instrum. Meth. A550, 169–184 (2005)

Speaker: Mr Dmitry Averyanov (NRC "Kurchatov Institute")

Abstract for Nucleus-2022.docx

10:00 → 11:40 Experimental and theoretical studies of nuclear reactions: NR1

Convener: V Varlamov (Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia)

10:00 OBSERVATION OF THE SHAPE ISOMER STATES IN FISSION FRAGMENTS FROM (γ, f) REACTIONS

The experiments were performed at the beam of the MT-25 microtron, FLNR, JINR, using VEGA (V–E Guide based Array) setup. Fission fragments (FFs) from the $^{235, 238}$U ($ɣ, f$) reactions are captured by the electrostatic guide system (EGS). The EGS constitutes a cylindrical capacitor of four meters long with a thin wire as a central electrode. Some part of the ions emitted from the target at one end of the guide can be involved in the spiral-like movement along the guide axis [1]. By this way the FFs are transported to the time-of-flight mass-spectrometer consisted of the microchannel-plates based timing detector and the mosaic of four PIN diodes. The mean time-of-flight of the FFs in the EGS exceeds 400 ns.
The peculiarities of the two dimensional FFs mass correlation distributions observed let us to suppose the following nature of such peculiarities (linear structures) [2]. Very deformed FF from binary ($ɣ, f$) reaction undergoes a break-up crossing the Lexan foil of the timing detector due to inelastic Coulomb scattering. It is possible if the fragment was born in the shape isomer state with a typical life time of more than 400 ns. Earlier, manifestations of similar process in $^{252}$Cf(sf) and $^{235}$U($n$$_{th}$, $f$) we discussed in Ref. [3].

Speaker: Dmitry Kamanin (JINR)

nucleus-2022-abstract-Kamanin.docx

10:20 Influence of the entrance channel asymmetry on the fission properties of excited 180Hg nuclei

Influence of the entrance channel asymmetry on the fission properties of excited $^{180}$Hg nuclei

K.A. Kulkov$^{1,2}$, E.M. Kozulin$^{1,2}$, A.A. Bogachev$^1$, G.N. Knyazheva$^{1,2}$, I.M. Itkis$^1$, K.V. Novikov$^{1,2}$, I.V. Vorobiev$^1$
$^1$Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research (JINR), Dubna, Moscow oblast, 141980 Russia
$^2$Dubna State University, Dubna, Moscow oblast, 141982 Russia
E-mail: kulkov@jinr.ru

Fission of the pre-actinide nuclei is characterized as predominantly symmetrical even at low excitation energies. Recently, in experiments on the β$^+$-delayed fission of the $^{180}$Tl nucleus [1], an asymmetric mass distribution of the fission fragments of its daughter nucleus $^{180}$Hg with an excitation energy
E$^*$<10.8 MeV was found. Note that the formation of two fragments – semimagic nuclei $^{90}$Zr (N = 50, Z = 40) – should be expected in the symmetric fission of this strongly neutron-deficient nucleus. However, the formation of a light fragment with a mass of 80 u and a heavy one of 100 u was found in the fission of $^{180}$Hg. Therefore, the study of the fission properties of pre-actinide nuclei is extremely important.
Thus, we propose to study reactions $^{36}$Ar+$^{144}$Sm and
$^{90}$Zr+$^{90}$Zr, leading to the formation of the compound nucleus 180Hg in the wide range of excitation energies. In the $^{36}$Ar+$^{144}$Sm reaction fusion-fission and fast fission are observed. Special M-TKE matrix subtraction procedure [2] allowed to separate these two processes. The reaction $^{90}$Zr+$^{90}$Zr was measured in wide energy range. The mass asymmetry of the entrance channel in this reaction is equal to 0. At high incident energies all three possible reaction mechanisms - fusion-fission, quasifission and fast fission - contribute to the M-TKE distributions of the fissionlike reaction products. The separation of the two-dimensional M-TKE distributions of binary fragments corresponding to different reaction mechanisms allowed to obtain the main characteristics of each process. Double-arm time-of-flight spectrometer CORSET was used to measure M-TKE distributions.

1. A.N. Andreyev, J. Elseviers, M. Huyse et al., Phys. Rev. Lett. 105, 252502 (2010).
2. E.M. Kozulin et al., Phys. Lett. B 819 (2021) 136442.

Speaker: Kirill Kulkov (JINR)

Kulkov. NUCLEUS-2022 abstract.docx

10:40 PHOTOFISSION OF 238U IN THE ENERGIES RANGE OF GIANT DIPOLE RESONANCE

The yields and average cross sections of the photonuclear reactions $^{238}U(\gamma,n)$ and $^{238}U(\gamma,F)$ are measured at a maximum bremsstrahlung energy of 55 $MeV$. Based on the analysis of the residual activity spectra of the products of the $^{238}U(\gamma,F)$ photofission reaction, the cumulative yields were measured for about 40 mass chains. The cross sections for the reactions $^{238}U(\gamma,n)$ and $^{238}U(\gamma,F)$ are estimated and compared with the results of experiments on quasi-monochromatic beams, estimated cross sections, and calculations using the TALYS program. The post-neutron mass yield distribution of $^{238}U(\gamma,F)$ photofission has been obtained (fig. 1). The behavior of the symmetric and asymmetric modes of photofission is analyzed as a function of the average excitation energy of the fissile nucleus.

Fig. 1. Approximation by five Gaussian functions of the total mass distribution $Y_{M}(A)$ of products formed as a result of $^{238}U$ photofission induced by bremsstrahlung photons at an electron accelerator energy of 55 $MeV$.

Speaker: Omar Albaghdadi

PHOTOFISSION OF 238U IN THE ENERGIES RANGE OF GIANT DIPOLE RESONANCE.docx

11:00 Fission modes in 238Np populated by 6Li+232Th

The mass-total kinetic energy(M-TKED) of fission fragments of the reaction 6Li+232Th were measured at two laboratory energies Elab = 28.5 and 40 MeV [1] using the CORSET set up at the Flerov Laboratory of Nuclear Reaction. The transfer induced fission and/or the breakup of 6Li mainly into α and d clusters contributes to the incomplete fusion in this reaction. The binary events within the gate of 180±3.5 degree in the fission fragment folding angle distribution have only been considered discarding the incomplete fusion events, for multi-modal analysis.

Two dimensional M-TKEDs of the binary fragments of 6Li+232Th, have been described by the multi-modal random neck rupture (MM-RNR) model [3]. Three modes were necessary to fit the data properly. Channel probabilities and the characteristics of different fission modes are obtained and discussed. The average kinetic energy <TKE> release in fission obtained from Viola systematic [4] matches well with that of the Standard 2 mode, but not with that of broad liquid drop like Superlong mode. This is associated with the decrease of the total kinetic energy associated with asymmetric fission with increasing excitation [5, 6] due to fading out of shell effects at high excitation energies. The slope of asymmetric to symmetric fission yields (when plotted against the excitation energy) of 6Li+232Th is found to be similar to that of previously reported 18O+208Pb.

1. I. M. Itkis et al., Phys. Lett. B640, 23 (2006)..
2. E. M. Kozulin et al., Instrum. Exp. Tech. 51, 44 (2008).
3. U. Brosa, S. Grossmann and A. Müller, Phys. Rep. 197, 167 (1990).
4. V. E. Viola Jr., Nucl. Data Sheets A1, 391 (1966); V. E. Viola, K. Kwiatkowski, and M. Walker, Phys. Rev. C 31, 1550 (1985).
5. A. Pica et al., Phys. Rev. C 102, 064612 (2020).
6. V. Yu. Denisov, I. Yu. Sedykh, Phys. Lett. B 824, 136814 (2022).

Speaker: Dr Tathagata Banerjee (Joint Institute for Nuclear Research, Dubna, Russia)

Nucleus22_abstract_Tathagata.docx

10:00 → 11:40 Experimental and theoretical studies of nuclear reactions: NR2

Convener: Юрий Чувильский

10:00 TIME-DEPENDENT MICROSCOPIC DESCRIPTION OF FAST ALPHA PARTICLES EMITTED IN NUCLEUS-NUCLEUS COLLISIONS

Appearance of new experimental data on the energy spectra of fast alpha particles emitted in heavy-ion reactions [1,2] requires development of microscopic models of such processes. The mechanism of nonequilibrium emission of alpha particles after capture of the projectile nucleus by the target nucleus is studied within the microscopic approach based on the time-dependent Schrödinger equation for the wave function of an alpha particle [1,3] (Fig. 1). Transfer of energy from the colliding nuclei to the alpha particle is studied in the quantum three-body one-dimensional time-dependent model [4]. The possibility of cooling of superheavy compound nuclei via emission of fast alpha particles (e.g., in the reaction ) is discussed.

Fig. 1. Evolution of the wave function of emitted alpha particle in the collision of `${}^{48}$Ca + ${}^{197}$Au at beam energy 280 MeV.

1. Yu. E. Penionzhkevich, V. V. Samarin, V. A. Maslov et al., Phys. At. Nucl. 84, 115 (2021).
2. Yu. E. Penionzhkevich, S. M. Lukyanov, V. A. Maslov et al., Phys. At. Nucl. 85, 145 (2022).
3. V. V. Samarin, Phys. At. Nucl. 81, 486 (2018).
4. V. I. Zagrebaev and V. V. Samarin, Phys. At. Nucl. 70, 1003 (2007).

Speaker: Prof. Viacheslav Samarin (Joint Institute for Nuclear Research)

1Samarin_nucleus-2022-abstract-alpha.docx

10:20 Sub Coulomb barrier d+208Pb scattering in the time-dependent basis function approach

We investigate the scattering of the deuteron on 208Pb below the Coulomb barrier based on the non-perturbative time-dependent basis function (tBF) approach[1]. We obtain the bound and discretized scattering states of the projectile, which form the basis representation of the tBF approach, by diagonalizing a realistic Hamiltonian in a large harmonic oscillator basis.
We find that the higher-order inelastic scattering effects are noticeable for sub barrier scatterings with the tBF method. By considering all the possible electric dipole (E1) transition paths among all the states involved in the tBF approach and taking into account the corrections of the polarization potential to Rutherford trajectories, we have successfully reproduced experimental sub Coulomb barrier elastic cross section ratios with the tBF approach. We find that both the internal E1 transitions of the deuteron projectile and the corrections of the polarization potential to the classical Rutherford trajectories are essential for reproducing experimental data in these sub barrier experiments. More specifically, the correction of the polarization potential to the Rutherford trajectory is dominant in reproducing the data at very low bombarding energies, whereas the role of internal transitions of the deuteron projectile induced by the E1 interaction during the scattering becomes increasingly significant at higher bombarding energies.

1. Peng Yin, Weijie Du, Wei Zuo, Xingbo Zhao, James P. Vary, arXiv: 1910.10586 [nucl-th].

Speakers: Peng Yin, Xingbo Zhao (Institute of Modern Physics, Chinese Academy of Sciences) , James P. Vary

nucleus-2022-abstract_PY.docx

10:40 VELOCITY DISTRIBUTIONS OF PROJECTILE-LIKE FRAGMENTS IN FRAGMENTATION REACTIONS AT FERMI ENERGIES

VELOCITY DISTRIBUTIONS OF PROJECTILE-LIKE FRAGMENTS IN FRAGMENTATION
REACTIONS AT FERMI ENERGIES

T. I. Mikhailova1, B. Erdemchimeg1,2, Yu. M. Sereda1
1Joint Institute for Nuclear research, Dubna, Russia;
2 National University of Mongolia, NRC, Ulaanbааtar, Mongolia
E-mail: tmikh@jinr.ru

Fragmentation reactions at Fermi energies are studied for decades since 1970th. They are of interest because in these reactions nuclei far from stability line are produced. The properties of these exotic nuclei can shed light on better understanding the nature of nuclear forces. The striking feature of heavy-ion induced fragmentation reactions is that the velocities of projectile-like fragments are peaked at projectile velocity. This would be natural for the reactions at relativistic energies in which direct processes prevail, but not so evident at lower ones which have dissipative nature. It is therefore of interest to understand in detail the production mechanism of these fragments. In these report we analyze velocity distributions of forward emitted fragments for several reactions on Be and Ta targets at energies in the vicinity of Fermi energy in terms of microscopic approach [1]. We also deduce the ratio of direct and dissipative components [2] as a function of mass fragment and study its dependence on the projectile energy and other characteristics of the reaction. This can be helpful in planning future experiments with radioactive beams.

1 T. I. Mikhailova et al., EPJ Web of Conferences. 173. 04010 (2017).
2 B. Erdemchimeg et al., Bulletin of RAS: Physics. 85. 1457. (2021).

Speaker: Tatiana Mikhailova (JINR)

406-nucleus_2022_TM.doc

11:00 Influence of cluster structure to the mechanism of nuclear reactions

In the interaction reactions of weakly bound cluster nuclei, the structure of these nuclei can manifest itself with a high probability. It is expressed in cross sections for these processes, in particular, in the multinucleon transfer reaction and the transfer reaction of individual clusters [1,2].
In order to study the influence of the cluster structure on the mechanism of nuclear reactions, we studied the interaction reactions 6Li+9Be,12C at an energy of 68 MeV. The experiment has been performed at the U-400M cyclotron, FLNR, JINR. The angular distributions of the products formed in these reactions were measured in the range of 10-120 º in the c.m system. The following reaction channels were studied: 9Be(6Li,6Li)9Be, 9Be(6Li,7Li)8Be, 9Be(6Li,6He)9B, 9Be(6Li, 4He)11B, 12C(6Li,6Li)12C, 12C(6Li,7Be )11B in ground and excited states. The obtained experimental data were analyzed within the framework of the optical model and the DWBA method [3].

1. Yu E Penionzhkevich, R.G. Kalpakchieva, Light Exotic Nuclei Near the Boundary of Neutron Stability, World Scientific Publishing Co Pte Ltd (2021)
2. Yu E Penionzhkevich, et.al, Eur. Phys. J. A 31, 185-194 (2007)
3. NRV web knowledge base on low-energy nuclear physics.http://nrv.jinr.ru/.

Speaker: Talgat Issatayev (JINR)

issatayev_talgat.ppt

nucleus-2022-abstract-Issatayev_final_eng.docx

11:20 MODELLING OF THE CLUSTER FORMATION IN HEAVY NUCLEI FISSION

This paper presents a study on the microscopical modelling of the cluster formation in the cold fission of actinides.
In the last three decades, the situation in experimental and theoretical investigation of clustering effects in multimodal fission has changed dramatically [1,2,3].
Based on our cold fission multi-valley calculations in the framework of Strutinsky shell correction method, a theoretical study of various cluster structures emerging in the process of fission has been carried out. Results have demonstrated the effect of the arrangement and rearrangement of magic clusters in the fission process [4,5].
This type of the cluster formation modelling has been successfully implemented for the flow turbulence control using air pressure sensors and aircraft wing surface modifying actuators [6]. For the first time a new approach to the emergent cluster aggregation by the local rules of interaction has been proposed in highly-cited work of Vicsek et al. [7].
Our computable microscopical modelling of the clustering can contribute to understanding of the fission process dynamical features such as a time scale, an interplay between collective and single-particle degrees of freedom and a degree of equilibration on the fission path.

1. Y. Pyatkov and D. Kamanin, J. Phys.: Conf. Ser. 1390 012011 (2019).
2. W. Oertzen and A. Nasirov, The European Physical Journal A. 56 (2020).
3. D. Rodkin, Yu.Tchuvil'sky, JETP Letters, 109:7, 425–431 (2019).
4. A. Unzhakova and O. Granichin, Exotic Nuclei: Proceedings, 351-354 (2020).
5. A. Unzhakova, T. Khantuleva, and O. Granichin, Fission and Properties of Neutron-Rich Nuclei: Proceedings, 582-589 (2018).
6. O. Granichin, T. Khantuleva, and N. Amelina, Proceedings IFAC, 1940 (2017).
7. T. Vicsek, A. Czirók, E. Ben-Jacob, I. Cohen, and O. Shochet, Phys. Rev. Lett. 75, 1226 (1995).

Speaker: Anna Unzhakova (Saint Petersburg State University)

unzhakova.docx

10:00 → 11:40 Intermediate and high energies, heavy ion collisions

Convener: Igor Pshenichnov (INR, Moscow and MIPT)

10:00 Energy dependence of triangular flow for identified hadrons in Au+Au collisions at $\sqrt{s_{NN}} = 14.5 - 62.4$ GeV from the STAR experiment

Author: Alexey Povarov (for the STAR Collaboration)
National Research Nuclear University MEPhI, Moscow, Russia
E-mail: povarovas@gmail.com

Heavy-ion collisions create matter which is characterized by high temperature and energy density, called Quark-Gluon Plasma (QGP). One of the methods for studying the transport properties and equation of state of the created matter is the measurement of azimuthal anisotropy of particles using the Fourier expansion of the azimuthal angle with respect to the event plane. The second order Fourier coefficient $\upsilon_{2}$ is called elliptic flow and is sensitive to the pressure gradients arising in the region of overlapping nuclei. The third order coefficient $\upsilon_{3}$ (triangular flow) is sensitive to the fluctuations of nucleons in the initial state of colliding nuclei and therefore $\upsilon_{3}$ weakly depends on the collision centrality. Theoretical studies show that $\upsilon_{3}$ is more sensitive to viscous effects than $\upsilon_{2}$, making triangular flow an ideal harmonic for studying the viscosity.

This work is devoted to the study of triangular flow in a wide energy range of Au+Au collisions from the STAR experiment at RHIC ($\sqrt{s_{NN}}$ = 14.5, 19.6, 27, 39, 62.4 GeV). New measurements of triangular flow will be presented as a function of particle transverse momenta ($\text{p}_{\text{T}}$) and collision energy. Physics implications will be discussed.

Speaker: Alexey Povarov (NRNU MEPhI)

aspovarov_abstract_nucleus_2022_0.docx

ASPovarov_Abstract_Nucleus2022_ver3_0.pdf

ASPovarov_NUCLEUS_2022_pres_ver5.pdf

10:20 Pion femtoscopy in Au+Au collisions at sqrt(sNN) = 3 GeV in the STAR experiment

Pion femtoscopy in Au+Au collisions at $\sqrt{s_{NN}} = 3$ GeV in the STAR experiment

A. Kraeva (for the STAR Collaboration)
E-mail: annakraeva555@gmail.com
National Research Nuclear University MEPhI, Kashirskoe highway 31, Moscow, 115409, Russia

There is a method that allows directly measuring the spatio-temporal extent of the region where hadrons are emitted and the parameters of the nuclear-nuclear interaction, called femtoscopic correlation [1]. In heavy-ion collisions, femtoscopy is an important tool for studying the geometric and dynamic characteristics of the emission region.
Two-particle momentum correlations of identical particles in nuclear-nuclear collisions make it possible to extract femtoscopic parameters (radii of emission region, $R$, and correlation strength, $\lambda$) [2]. Reaction dynamic is reflected in the femtoscopic radii dependence on pair transverse momentum, $k_T$.
This work is devoted to the study of two-particle momentum correlations of identical pions produced in collisions of gold nuclei in the STAR experiment at the RHIC at $\sqrt{s_{NN}} = 3$ GeV. The extracted three-dimensional femtoscopic radii ($R_{out}$, $R_{side}$, $R_{long}$) are measured as a function of collision centrality and transverse momentum of the pairs.

References:
[1] Podgoretsky M.I. Interference correlations of identical pions, Sov. J. Nucl. Phys. – 1989. – V.20. – P.3.
[2] Lisa M.A. et al. Femtoscopy in relativistic heavy ion collisions: two decades
of progress, Annu. Rev. Nucl. Part. Sci. – 2005. – V.55. – P.357.

Speaker: Anna Kraeva

Nucleus_2022_abstract_Kraeva_Anna.docx

Nucleus2022_Kraeva_v5.pdf

10:40 Femtoscopic probes in collisions of small and large systems from STAR

One of the goals of ion-ion collision studies is to understand mechanism of particle production and reveal the properties of particle-emitting source. A quark-gluon matter, produced in collisions of relativistic heavy ions at high energies ($\sqrt{s_{NN}}\ge$62.4 GeV), undergoes a rapid transition to the hadronic matter known as crossover [1]. At lower collision energies it is expected that the phase transition will be of the first order [2] that also implies an existence of the critical point [3]. The change of phase transition type may be imprinted on the spatial and temporal properties of the particle-emitting source. The correlation femtoscopy method, based on the measurement of two-particle momentum correlations arising due to the quantum statistical correlations, is designed to access space-time extents of the fireball [4]. In addition to the large collision systems, it is also important to obtain the information about the particle production mechanism in small collision systems.

In this talk, we report the results of the two-particle femtoscopic correlations measured in collisions of small and large systems (including p+Au and Au+Au) from the STAR experiment at RHIC. The physics implications will be discussed.

References:
[1] Abdallah M.S., et al. Measurement of the sixth-order cumulant of net-proton multiplicity distributions in Au+Au collisions at in Au+Au collisions at √sNN = 27, 54.4, and 200 GeV at RHIC, Phys. Rev. Lett. - 2021. - V. 127. - P. 262301.
[2] Ejiri, S. Canonical partition function and finite density phase transition in lattice QCD, Phys. Rev. D. - 2008. - V. 78. - P. 074507.
[3] Stephanov, M. QCD phase diagram and the critical point, Prog. Theor. Phys. Suppl. - 2004. - V. 153. - P. 139.
[4] Lisa M.A. et al. Femtoscopy in relativistic heavy ion collisions: two decades of progress, Annu. Rev. Nucl. Part. Sci. – 2005. – V.55. – P.357.

Speaker: Grigory Nigmatkulov

365-Nigmatkulov_nucleus_2022_abstract.docx

Nigmatkulov_Nucleus2022_v4.pdf

11:00 Study of NCQ scaling of elliptic and triangular flow for identified hadrons in Au+Au collisions at $\sqrt{s_{NN}} = 11.5 - 200$ GeV

A main purpose of Beam Energy Scan experiments is to study the properties of the Quark-Gluon-Matter (QGM) forming in the collisions of two nuclei. Anisotropic flow of produced particles is one of the important observables sensitive to the transport properties of the QGM created in relativistic heavy-ion collisions. Anisotropic flow of identified particles measured in Au + Au collisions at top RHIC energy $\sqrt{s_{NN}} = 200$ GeV exhibits a remarkable NCQ scaling with number of constituent quarks and transverse kinetic energy.
In this work, we report on the calculations of elliptic (v2) and triangular (v3) flow of identified charged hadrons produced in Au+Au collisions at 11.5 −200 GeV from several state of the art models and provide the direct comparison with published results from RHIC BES experiments.
Further insights about the mechanism of NCQ scaling of anisotropic flow will be discussed.

Speaker: Aleksandr Demanov (NRNU MEPhI)

405-nucleus-2022-abstract-Demanov.docx

10:00 → 11:40 Nuclear structure: theory and experiment

Convener: Dmitri Eremenko

10:00 First experiment at the Super Heavy Element Factory. New data in the 243Am + 48Ca reaction.

We present results of the first experiments aimed at the synthesis of Mc isotopes in the 243Am+48Ca reaction performed at the new gas-filled separator DGFRS-2 on-line to the new cyclotron DC280 at the SHE Factory at JINR. One hundred-ten new decay chains of 288Mc, four new decay chains of 287Mc and ten chains assigned to 289Mc were detected. The α-decay of 268Db with an energy of 7.6-8.0 MeV, half-life of 16(+6 -4) h, and a branch of 55(+20 -15) was registered for the first time, and a new spontaneously fissioning isotope 264Lr with a half-life of 4.9(+2.1 -1.3) h was identified. Decay chain of the new superheavy isotope 286Mc has been registered. We firstly observed spontaneous fission of 279Rg. The cross section for the 243Am(48Ca,3n)288Mc reaction was measured to be 17.1(+6.3 -4.7) pb, which is the largest value for a superheavy nucleus at the Island of Stability. The cross section of 243Am(48Ca,5n)286Mc was measured for first time.

Speaker: Nikita Kovrizhnykh (Joint Institute for Nuclear Research)

nucleus-2022-abstract-Nikita-Kovrizhnykh.docx

10:20 Detailed study of radioactive decay properties of nobelium isotopes with α, β, γ-spectroscopy method

At FLNR JINR, experiments are aimed to investigate the radioactive decay properties ($\alpha$, $\beta$, $\gamma$-spectroscopy) and the cross sections measurements of transfermium elements, synthesized in complete fusion reaction of accelerated heavy ion beam with target nuclei, with subsequent evaporation of several light particles at the kinematic separator SHELS [1,2]. A number of experiments were devoted to the study of the radioactive decay properties of Nobelium isotopes are produced as an evaporation result of two or three neutrons by a compound nucleus in the reaction of $^{48}$Ca beam with $^{204,206,208}$Pb targets. These Nobelium isotopes have sufficiently high production cross-sections, which allow us collect good statistics for studying decay properties by methods of alpha, beta, gamma spectroscopy. Nobelium isotopes are interesting in how the radioactive decay properties change passing through the closed subshell N = 152, thereby could be obtain data are necessary to understanding how the heavy elements properties behave passing through the subshell N = 162.

1. A. V. Yeremin, et al., Phys. Part. Nucl. Lett. 12, 43 (2015).
2. A. V. Yeremin, et al., Phys. Part. Nucl. Lett. 12, 35 (2015).

Speaker: Mereigul Tezekbayeva (Joint Institute for Nuclear Researches, Flerov Laboratory of Nuclear Reactions)

nucleus-2022-abstract-Tezekbayeva M.docx

10:40 The multiplicity of neutrons of spontaneous fission of 250No obtained in complete fusion reactions with heavy ions at the SHELS separator.

For more than 20 years, experiments on the synthesis and study of the properties of radioactive decay of short-lived isotopes of transuranic elements have been conducted at the Flerov Nuclear Reactions Laboratory of JINR. The reactions of complete fusion of accelerated multicharged ions with target nuclei heavier than lead were mainly used. In these experiments, experimental installations with kinematic separation of recoil nuclei from background products are most often used. In these installations (separators), the separation in space of recoil nuclei, incoming ions and products of multi-nucleon transfer reactions occurs in electric and magnetic fields due to the difference in their trajectories caused by the difference in their ionic charge and energy (velocity) distributions.
This work describes the kinematic separator SHELS [1], which is used for the synthesis and study of the properties of heavy nuclei. A separator detection system consisting of a time-of-flight system, a focal semiconductor detector and a SFiNx detection system is described [2]. The new detection system consists of an assembly of multi-strip two-sided Si detectors, around which 116 proportional neutron counters filled with 3He are placed. The detector system was used in the experiment to study the characteristics of spontaneous fission of the isotope 250No, in which data on the yields of neutrons of spontaneous fission were compared with previously published results.
Preliminary data were obtained during processing. The neutron detection efficiency was (54.7 ± 0.1)%. The measured average number of neutrons in the 250No fission act was (2.32 ± 0.07), which, taking into account the efficiency of the neutron detector, gives the value of the average number of neutrons ν = (4.24 ± 0.13).

1. Popeko A.G., Yeremin A.V., Malyshev O.N., Chepigin V.I., Isaev A.V., Popov Yu.A., Svirikhin A.I., Haushild K., Lopez-Martens A., Rezynkina K., Dorvaux O. Separator for Heavy ELement Spectroscopy – velocity filter SHELS. // Nucl. Instrum. Methods Phys. Res. B. 2016. 376. P. 140–143.
2. A.V. Isaev et al. The SFiNx Detector System. // Physics of Particles and Nuclei Letters 19.1 (2022), pp. 37–45.

Speaker: Mr Bekzat Sailaubekov (Joint Institute for Nuclear Research, Dubna, Russia)

Thesis Sailaubekov B..docx

11:00 Neutron multiplicity distributions for 250No spontaneous fission from ground state or at the decay of the isomeric state

The spontaneous fission is one of the decay channel on a par with α- and β+-decays for heavy and super-heavy isotopes (Z > 100). There are no established models that could describe all details of spontaneous process well yet. Therefore, experimental studies of such processes are high-interesting and important.

The combination of relatively high formation cross-section in complete fusion reactions and discovered K-isomer state living longer than its ground state [1] makes 250No isotope attractive to experimental study. The SHELS separator [2] and SFiNx detection system [3] at FLNR JINR, Dubna, Russia allows us carrying out experiments to study prompt neutron yields from 250No spontaneous fission.

The previous experiment [4] hinted at possibility of spontaneous fission directly from an isometric state 250mNo. The difference between average numbers of neutrons per fission with corresponding lifetimes (for ground and isometric states) was quite large but statistically insignificant (≈2σ). Thus, conclusion about spontaneous fission from isomeric state possibility couldn’t be drawn.

In the beginning of the 2022 the new experiment was carried out using modern analysis techniques and the detectors array with higher efficiency than in the previous one [4]. Approximately 1350 spontaneous fissions of 250No were registered (vs ≈700 in [4]). Two activities with different lifetimes associated with 250No and 250mNo were observed. The difference between average numbers of emitted spontaneous fission prompt neutrons for both activities are statistically insignificant (<1σ). Prompt neutrons multiplicity emission probability distributions for both activities separately and combined were restored using statistical regularization method [5].

The prompt neutron multiplicities distributions restoring technique will be discussed in the report. Furthermore, the structure of such distributions will be shown in conjunction with theoretical interpretation of processes.

1. J. Kallunkathariyil et al., Phys. Rev. C 101, 011301 (2020)
2. A.G. Popeko et al., NIMB, 376, 140-143 (2016)
3. A.V. Isaev et al., Phys. of Part. and Nucl. Let., 19, 1 (2022)
4. A.I. Svirikhin et al. Phys. of Part. and Nucl. Let., 14, 4 (2017)
5. R.S. Mukhin et al., Phys. of Part. and Nucl. Let, 18, 4 (2021)

Speaker: Roman Mukhin (Joint Institute for Nuclear Research)

151-nucleus-2022-abstract-Mukhin (1).docx

11:20 Study of the 242Pu + 48Ca and 238U + 48Ca reactions at DGFRS-II

This work presents the results of the experiments performed at the FLNR, JINR Superheavy Element Factory (SHE Factory). The experiments were carried out on the basis of the new cyclotron DC-280 with an intensity of accelerated particles of up to 10 pµA [1] and gas filled separator DGFRS-2 [2] and were aimed at study of the $^{242}$Pu+$^{48}$Ca and $^{238}$U+$^{48}$Ca reactions. The main goal of this experiments consisted in determining the capabilities of the SHE Factory for the production and study of new isotopes of known superheavy elements up to Og(Z=118), as well as the synthesis of new ones with Z>118.
The decay properties of $^{286}$Fl and $^{287}$Fl, as well as their α-decay products, have been updated from 25 and 69 new decay chains, respectively. Additionally, 16 decay chains of $^{283}$Cn were observed in the $^{238}$U+$^{48}$Ca reaction. During the experiment, the maximum intensity of the $^{48}$Ca ion beam was 6.5 pµA. The stability of the target was measured at such high intensities. Possibility of existing of isomeric states in the $^{287}$Fl consecutive α decays is discussed. A new α line with energy of 100-200 keV lower than the main one at 10.19 MeV was observed for the first time for even-even $^{286}$Fl. The maximum cross section of 10.4$^{+3.5}_{-2.1}$) pb was measured for the $^{242}$Pu($^{48}$Ca,3n)$^{287}$Fl reaction.

1. G.G. Gulbekian S.N. Dmitriev, M.G. Itkis, Yu.Ts. Oganessyan, B.N. Gikal et. al. Start-Up of the DC-280 Cyclotron, the Basic Facility of the Factory of Superheavy Elements of the Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research. // Phys. Part. Nucl. Lett. 16, 866 (2019).
2. Yu.Ts. Oganessian, V.K. Utyonkov et al. DGFRS-2 - a gas-filled recoil separator for the Dubna Superheavy Element Factory. // Nuclear Instruments and Methods in Physics Research (submitted).

Speaker: Mr Dastan Ibadullayev (1. FLNR, JINR. 2. Institute of Nuclear Physics, Almaty)

Abstract_Ibadullayev_Nucleus_2022.docx

10:00 → 11:40 Nuclear technology and methods in medicine, radioecology.

10:00 Современные возможности ядерной медицины в кардиологии

...

Speaker: Prof. Simon Matskeplishvili (MSU)

10:20 ACTUAL NUCLEAR MEDICINE PROBLEMS IN PEDIATRICS

The current state and prospects for the development of nuclear medicine in pediatrics was analyzed on the basis of literature data and own experience. The main directions of radionuclide diagnostics and radionuclide therapy in children were considered briefly. There is a quantitative predominance of radionuclide diagnostic studies in pediatric urology compared to studies in oncology. Radionuclide therapy in children are used much less often and mostly for the hyperthyroidism, differentiated thyroid cancer and neuroendocrine tumors.
Currently the most important problem is the exact determination of the individual optimal activity of the radiopharmaceutical administered to a child. The technology is based on body weight and the protocol on a specific device. In the first approximation, this problem is solved by the reference diagnostic levels of activity. At the same time, the impossibility of obtaining an exhaustive solution to the problem of individualization on the basis of the current domestic regulatory documentation was stated, although methods for the refined calculation of the specified activity for the most commonly used diagnostic radiopharmaceuticals in pediatrics have already been proposed and validated by international specialized organizations. In radionuclide therapy for children, optimal activity is determined by the theranostics principles and technologies.
The widespread introduction into clinical practice of hybrid devices for radionuclide research leads to radiation exposure increase to pediatric patients, when internal radiopharmaceutical dose is supplemented by a higher dose of external radiation from X-ray CT. Methods for determining organ and effective doses of diagnostic exposure of children are analyzed. It is noted that the errors in the indicated radiation doses determining on the basis of domestic regulatory documentation and international recommendations reach several tens of percent, what is significantly worse than the other radiation therapy methods accuracy.
When compiling the list of clinical indications for nuclear medical procedures in children, there is the need of taking into account the risk of radiation-induced carcinogenesis. In the case of radionuclide therapy its probability in children is significantly higher. The possibility and expediency of risk assessment based on the concept of effective radiation risk instead of the concept of effective dose is discussed. It also requires the development of appropriate methodological recommendations, including the international level.
The technological and psychological features of nuclear medical procedures in children are discussed together with a higher complexity of their implementation. Practical recommendations for such cases are presented.

Speaker: Dr B.Ya. Narkevich

Narkevich nucleus 2022.docx

10:40 ADVANCED HADRON THERAPY TECHNOLOGIES BASED ON THE BINARY NUCLEARPHYSICS METHODS

The program of development and implementation of new diagnostic and therapy technologies based on the Proton Therapy Complex (PTC) "Prometheus" is presented. The tasks will be implemented with the close integration of the LPI, MEPhI, Center of Radiology of RF, as well as their Russian and foreign partners.
Modernization of Russian-made proton synchrotron complexes of the Prometheus system is envisaged in order to develop and implement new technologies based on them and improve existing technologies for proton and ion therapy and diagnostics. Prometheus is a unique PTC. It is a compact (outer diameter - 5 m, weight – 15 tons) synchrotron for protons with low energy consumption (up to 100 kW), which allows one to place such PTCs directly in medical centers.
It is supposed to develop proton radiography and tomography technologies using the maximum proton energy. Technologies of combined action of various types of radiation (protons-neutrons, protons-carbon ions, multi-ion therapy); targeted proton therapy technologies using promising nanoparticles and systems based on them as therapy sensitizers and active agents for diagnostics.
The latter direction involves a significant expansion of the field of modern nuclear medicine through integration with nanomedicine, which uses nanoparticles for the diagnosis and therapy of cancer, using their unique properties. The introduction of non-radioactive materials that can be activated from the outside using various external sources of nuclear particles to produce radioactivity in situ is one of the new directions of activation of nano-drugs at the site of a cancerous tumor, which can be considered as in situ production of radiopharmaceuticals [1].
Modernization of Prometheus PTC based on the developed nuclear physics technologies, their production for Russian nuclear medicine centers opens the way for solving the issue of development and introduction of new effective technologies for proton and ion diagnostics and therapy.

1. Roy I., Krishnan S., Kabashin A., Zavestovskaya I., Prasad P. Transforming Nuclear medicine with nanoradiopharmaceuticals. Review. ACS Nano. (2021).

Speaker: Dr I. N. Zavestovskaya

nucleus-2022-abstract-INZavestovskaya.docx

11:00 Analysis of cell response to ultrahigh dose-rate proton irradiation

As is known, the flash effect in radiotherapy with a dose rate of more than 40 Gy/s makes it possible to destroy tumor cells much stronger than normal cells. Additional prospects for flash therapy are associated with irradiation with protons, since protons and ions make it possible to increase the conformality of irradiation compared to irradiation with light particles. A unique feature of the proton beam facility at the Institute of Nuclear Research [1], is that it makes it possible to deliver the total irradiation dose in one pulse with a duration of less than 100 μs. Such a single-pulse flash mode (splash) of radiotherapy may open up additional prospects.
We have carried out a series of several runs of the INR proton accelerator in a wide range of modes: from the conventional mode with an average dose rate Ḋ < 3 Gy/s to the splash mode with Ḋ > 104 Gy/s. Two types of tumor cells were irradiated in these experiments: human colon adenocarcinoma (HT-29) and human colon cancer (HCT116). Human adipose tissue mesenchymal stem cells (ADSC) – fibroblasts – were taken as normal cells. Cell cultures were irradiated in the region of the Bragg peak (SOBP) and on the plateau up to the Bragg peak. The task is to carry out a comprehensive analysis of the cell response to various modes of proton irradiation, both using flow cytometry and using another method - real-time PCR. Quantitative PCR was used to analyze the genetic control of apoptosis initiation (BAX, PUMA genes), cell cycle control (CDKN1A gene), and genome integrity control (p53 gene).
According to preliminary results, the levels of expression of genes involved in apoptosis and genome integrity control under flash/splash irradiation differ from those under conventional irradiation both in the studied tumor lines and in normal fibroblasts.
The work is supported by the Russian Science Foundation grant No. 22-25-00211 “Investigation of cell response to the impact of record powerful ultrashort proton pulses.”

1. Akulinichev S.V., et al. Possibilities of Proton FLASH Therapy on the Accelerator at the Russian Academy of Sciences’ Institute for Nuclear Research. Bull. Russ. Acad. sci. Phys. 84, 1325–1329 (2020).

Speaker: Sergey Akulinichev (INR RAS, Hospital of RAS)

nucleus-2022-akulinichev.docx

11:20 DEVELOPMENT OF THE SPECIALTY "MEDICAL PHYSICS" IN THE REPUBLIC OF BELARUS

The main principles and requirements for the introduction of medical physics into medicine in the CIS countries were developed by the organizer of the Association of Medical Physicists of Russia and its first president, Professor Valery Aleksandrovich Kostylev, back in the last century. Now there are medical physicists in the Republic of Belarus.
By the Decree of the Ministry of Labor and Social Protection of the Republic of Belarus dated May 31, 2013 No. 49 “On Amendments and Additions to the Decree of the Ministry of Labor of the Republic of Belarus dated December 30, 1999 No. 159”, the position of “Medical Physicist” was introduced in the republic.
The Republican Institute of Higher Education, by changing No. 9 of the National Classifier of the Republic of Belarus 011-2009 “Specialties and Qualifications”, approved a new specialty of higher education of the first stage “Medical Physics”.
By the Decree of the Ministry of Health of the Republic of Belarus No. 55 dated April 12, 2016 “On approximate staffing standards for the oncological service”, the position of “Medical Physicist” was introduced in the republic.
The training of medical physicists in the Republic of Belarus is carried out at the International Sakharov Environmental Institute of Belarusian State University (ISEU BSU, since 2013. In 2017, a master's program in medical physics was organized at the ISEU named after A.D. Sakharov BSU. Master students underwent an in-depth study of all sections of medical radiology. Graduates of the institute work in most oncological institutions of the country, as well as in other institutions of the republic related to dosimetry, radiation safety, processing of information obtained in the diagnosis and treatment of patients, sanitary supervision, metrology, etc. In 2022, more than 80 medical physicists work in Belarus, and their number will increase every year for 10-15 people In addition to practical work in clinics, medical physicists actively participate in scientific research, including projects supported by the IAEA.
In 2018, a postgraduate course for medical physicists was opened at ISEU BSU. Unfortunately, the specialty “Medical physics” is not yet available in the Higher Attestation Commission of Belarus, and graduate students are preparing to defend dissertations in other specialties of technical sciences.

Speaker: Dr I.G. Tarutin

Tarutin nucleus 2022.docx

11:40 → 12:10 Coffee-break

12:10 → 13:55 Applications of nuclear methods in science and technology

Convener: Nikolay Chechenin (Lomonosov Moscow State University)

12:10 CALIBRATION OF RADIOISOTOPE DEVICES

In paper considered development method calibration radioisopote densitometer amd radioisotope level gauges in laboratory conditions.The tightness of Cs-137 closed radiation ionization sources was made by the immersion method. The radioisotope densitometers (Endress+Hauser AG, Switzerland) was calibrated using a special technique with using metal calibration container with liquid imitators based on a mixture of bromoform and ethyl alcohol having different densities. The radioisotope level gauge (Mesacon Messelektronik, GmbH Dresden) on a special stand using a mixture of bromoform and ethanol was calibrated.

Speaker: Ulugbek Ashrapov (senior scientific researcher)

nucleus-2022-abstract.docx

Калибровка радиоизотопного плотномера.ppt

12:35 TO TESTING OF THRESHOLD SILICA AEROGEL CHERENKOV DETECTORS ON COSMIC RAYS

At present, threshold aerogel Cherenkov detectors based on SiO2 with chosen refractive indices (hereinafter referred to as “threshold detectors”) are widely used for studies in physics of elementary particles (in particular, for separating charged pions and kaons, see about it, e.g., in [1] and in references therein). Since the number of Cherenkov photons is small compared to that from scintillators, it is required to test such threshold detectors and measure their significant characteristics on accelerator beams and / or on cosmic rays. In our case, the detector, when the entire aerogel block is viewed by a set of photomultiplier tubes (PMTs), such characteristics are the distribution of the number of “activated” PMTs, the total detection efficiency, etc.
Usually (see, e.g., [1]), at cosmic ray testing of some threshold detector, several horizontal plastics (viewed by their PMTs) form telescope around vertical axis. Signals from these detectors are used as a trigger for testing of the threshold detector placed on the same axis. In [1], layers of Pb with additional plastic detectors behind each Pb layer are installed ahead and behind the tested threshold detector to separate particles with energies higher than thresholds for production of Cherenkov radiation. However, because of complicated content of incident cosmic rays, initial distributions of their energies, and spreads of ionization losses, there are restrictions on definiteness of energies (and velocities) of the registered particles (mostly muons). Moreover, such testing installations are rather bulky and heavy.
In the present work instead of layers of Pb, we added to trigger detectors the small threshold detector which made from the same aerogel as the tested detector, installed just behind the tested detector, viewed by single PMT of the same type as for the tested threshold detector, and plays the role of Cherenkov monitor with its total detection efficiency close to 100%. This efficiency level is ensured by the small sizes of the aerogel (5 x 5 x 9 cm3) and of the PMT photocathode diameter (~5 cm). In our case, the number of Cherenkov photons in the photocathode sensitivity region (260 nm – 610 nm) generated by a muon in the Cherenkov monitor is about 200. Due to the small sizes of the monitor, a sufficient number of photons always hit the PMT photocathode for a signal to appear even when using PMTs with moderate quantum efficiency.

1. A.R. Buzykaev. Development of Cherenkov ASHPH counters for the KEDR detector. The candidate of sciences (physics – mathematics) dissertation. Budker Institute of Nuclear Physics. Novosibirsk. 2017.

Speaker: Leonid Dzhilavyan (Institute for Nuclear Research of the Russian Academy of Sciences)

39-nucleus-2022_abstract_39_Lapik, Dzhilavyan, et al..doc

13:35 Validation of nuclear de-excitation models of Geant4 toolkit

Geant4 is a powerful Monte Carlo modeling toolkit [1] to describe the propagation and interactions of particles and nuclei in various media. It was originally designed for experiments at the LHC, but its area of application is rapidly extending well beyond high energy physics to low energy nuclear physics, astrophysics, space science, medical physics and radiation protection [2].

Nuclear reactions induced by hadrons and nuclei are modeled by Geant4 as multistage processes. In particular, the Binary Cascade (BIC) [3] and Liege Intranuclear Cascade (INCL) [4] models are used to simulate the emission of fast particles at the first cascade stage resulting in an exited nuclear residue. Depending on the excitation energy calculated per nucleon of the residual nucleus E/A various decay processes take place. At E/A<2 MeV the evaporation of neutrons, protons and alpha-particles from residual nuclei [5] is modeled, while the Statistical Multifragmentation Model (SMM) [6] is employed to simulate the decays into nucleons and multiple nuclear fragments at higher excitation energies. Nuclear de-excitation models of Geant4 were validated in its early version of 9.1 [7].

In the present work we validate nuclear de-excitation models of recent Geant4 versions 10.4 and 11.0 by means of standalone tests for specific residual nuclei and excitation energies. Calculation results are compared to measured energy spectra of evaporated neutrons, protons and alpha-particles [8] and to charge distributions of secondary fragments calculated with FORTRAN version of SMM [6]. A detailed analysis of the momentum distributions of SMM products is performed and several suggestions to improve the results of the modeling were reported to Geant4 developers. After the revisions, the latest versions of de-excitation models of Geant4 can be used in our Abrasion-Ablation Monte Carlo for Colliders model (AAMCC) [9] to simulate the properties of spectator matter in collisions of relativistic nuclei.
[1] J. Allison et al., Nucl. Sci. IEEE Trans. 53 (2006) 270
[2] J. Allison et al., Nucl. Inst. Meth. A 835 (2016) 186
[3] G. Folger, V. Ivanchenko, H. Wellisch. Eur. Phys. J. A. 21 (2004) 407
[4] S. Leray et al., Nucl. Data Sheets 118 (2014) 312
[5] V.Weisskopf, Phys. Rev. 52 (1937) 295
[6] A.S. Botvina et al., Nucl. Phys. A. 584 (1995) 737
[7] I.A. Pshenichnov et al., Nucl. Inst. Meth. B 268 (2010) 604
[8] R.J. Charity, Phys. Rev. C 82 (2010) 014610
[9] R. Nepeivoda et al., Particles 5 (2022) 40

Speaker: Roman Nepeivoda (INR, Moscow and MIPT)

Nepeivoda_NUCLEUS_2022.docx

Nepeivoda_NUCLEUS_2022.pdf

nepeivoda_presentation_NUCLEUS_2022.pdf

nepeivoda_presentation_NUCLEUS_2022.pptx

12:10 → 13:50 Experimental and theoretical studies of nuclear reactions: NR1

Convener: V Varlamov (Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia)

12:10 ENERGY DEPENDENCE OF TOTAL REACTION CROSS SECTIONS FOR ISOTOPES OF Be ON TARGETS ${}^{28}$Si, ${}^{59}$Co, ${}^{181}$Ta

Energy dependence of the total cross sections σ${_{\rm{R}}}$(E) for reactions ${}^{10,11,12}$Be + ${}^{28}$Si, ${}^{59}$Co, ${}^{181}$Ta are presented. The 4π-methods of σ${_{\rm{R}}}$ measurements are based on registration of prompt γ-quanta and neutrons using a 12-module 4π-spectrometer [1]. The results of the two methods for calculating the total reaction cross sections are presented.

The values of σ${_{\rm{R}}}$ were calculated taking into account:

1. the mean detection efficiency <ε> of the 4π-spectrometer, which does not depend on γ-multiplicity M${_{{\gamma}}}$ [2];
2. the distribution of the numbers of triggered detectors during registration of the cascades of particles at a fixed value of multiplicity M${_{{\gamma}}}$.

Measurement of the detection efficiency ε(M${_{{\gamma}}}$) for various values of γ-multiplicity M${_{{\gamma}}}$ was carried out using the method described in [3].

1. Yu.G. Sobolev, Yu.E. Penionzhkevich, V.V. Samarin, M.A. Naumenko, S.S. Stukalov, I. Siváček, S.A. Krupko, A. Kugler, and J. Louko, Bull. Russ. Acad. Sci.: Phys. 84, 948 (2020).
2. Yu.E. Penionzhkevich, Yu.G. Sobolev, V.V. Samarin, and M.A. Naumenko, Phys. Atom. Nucl. 80, 928 (2017).
3. Yu.E. Penionzhkevich, Yu.G. Sobolev, V.V. Samarin, M.A. Naumenko, N.A. Lashmanov, V.A. Maslov, I. Siváček, and S.S. Stukalov, Phys. Rev. C 99, 014609 (2019).

Speaker: Sergey Stukalov (JINR, Dubna, Russia)

Stukalov1.docx

12:30 ASYMPTOTIC NORMALIZATION COEFFICIENTS AND THE NEUTRON WIDTHS FOR $^{30}$Si+n $\to ^{31}$Si FROM THE PERIPHERAL $^{30}$Si($d,p$)$^{31}$Si REACTION

Usually the differential cross sections (DCSs) of nucleon transfer reactions (NTR) are analyzed within the conventional DWBA for determination of a nucleonic spectroscopic factor S (SF) by normalization of the calculated DCS to the experimental data ([1] and references therein). The SF have strong dependence on the single-particle potential parameters. In contrast of the SF, the values of the asymptotic normalization coefficients (ANCs) [2] found from the analysis of the peripheral NTR are fairly weakly dependent on the single-particle potential parameters. The modified DWBA [3] and the dispersion peripheral pole model (DPPM) [4] can be used for determination of the ANCs from the analysis of the DCSs of the peripheral NTR. In both of these methods, the DCS is expressed in terms of the ANC for the removed nucleon from the residual nuclei. Nevertheless, the modified DWBA [3] can be applied when the residual nucleus in the reaction under consideration is formed only in bound (nonresonance) states, whereas the DPPM allows analyzing the DCS of the peripheral NTR populating to both bound and unbound states of the residual nucleus.
In the present work, the results of the analysis of the experimental DCSs for the $^{30}$Si($d,p$)$^{31}$Si reaction populating to the bound and unbound (resonance) states of the residual nuclei measured at the projectile deuteron energy 12.3 MeV [5] are presented. The analysis were performed within the framework of the DPPM [4] and MDWBA [3] with correct taking into account the three-body Coulomb dynamics in the transfer pole mechanism and Coulomb-nuclear distorted effects in the exit and entrance channels [6].
The analysis shows that the DCSs calculated within MDWBA [3] and DPPM [4] are in a good agreement with the experimental data. The new values of the ANC for $^{30}$Si+n $\to ^{31}$Si with their uncertainties corresponding to the bound states of the $^{31}$Si nuclei are obtained from the analysis of the experimental DCSs of the reaction $^{30}$Si($d,p$)$^{31}$Si within DPPM [4] and MDWBA [3]. The neutron widths for the resonance states of the 31Si nuclei are obtained from the analysis of the experimental DCSs of the reaction $^{30}$Si($d,p$)$^{31}$Si within DPPM [4].

REFERENCES
1. S.A.Goncharov et al., Yad.Fiz. 35(1982) 662
2. L.D.Blokhintsev et al., Sov. J. Part. Nucl.8(1977) 485
3. A.M.Mukhamedzhanov et al., Phys.Rev.C56(1997) 1302
4. E.I.Dolinskii, P.O.Dzahamalov, A.M.Mukhamedzhanov., Nucl.Phys.A202 (1973) 97.
5. S.Piskor, J. Novak et al., Nucl. Phys A 662 (2000) 112-124
6. G.V.Avakov et al., Sov. J.Nucl.Phys.43(1986)524

Speaker: Erkinjon Ikromkhonov (Institute of Nuclear Physics, Academy of Sciences of Uzbekistan)

12:50 CRYOGENIC GAS CATHER STOPPING ENERGY EFFICIENCY SIMULATION

The mass is a fundamental property of an atom comprising all information on its constituents and their interactions. Thus, it carries information on the internal structure of the nucleus, reveal the quantum mechanical shell structure within complex nuclei and determine the energy available for nuclear transformations in radioactive decay processes. Mass measurements allow us to benchmark nuclear models and thus contribute to investigations of the nature of the strong interaction itself. With the aim of high-precision mass measurement (HPMM) of heavy and super heavy elements, a new experimental setup is being built in FLNR, Dubna. The setup consists of the following parts: target unit; gas-filled separator of complete fusion reaction products; cryogenic gas stopping cell (CGSC); a radio-frequency system for transporting and cooling a low-energy beam; and a multi-reflection time of flight mass spectrometer (MR-TOF MS). CGSC is responsible for the final slowing down and thermalizing the energy-bunched fragments produced and selected in the Gas Filled Separator. The thermalization is achieved in a volume filled with ultra-pure helium gas at cryogenic temperatures. After the thermalization, the fragments are extracted and transported with a radio frequency quadrupole (RFQ) to the MR-TOF MS. The stopping and thermalization of the incoming fusion-evaporation residuals (EVRs) is a key step in HPMM of the heaviest elements. Due to the typically low incoming ion rates and low particle integrals CGSC has to be as efficient as possible. The HPMM requires at least a few ions for a measurement any loss should be avoided. The kinetic energy of the incident EVR, the entrance window foil type and thickness as well as the buffer-gas type and density of the CGSC condition the stopping efficiency. Only the ions that are stopped within the active gas volume of the CGSC can be extracted. The stopping efficiencies for EVRs cannot be tested on-line and one have to rely on simulations. To use the CGSC on ion beam the optimal entrance window foil thickness for every reaction is necessary evaluate. The Geant4 and SRIM software packages was used in these simulations with different entrance window materials and beam and target combinations.

Speaker: Alena Kohoutova (Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions, Joliot Curie 6, Dubna, Moscow region, 141980 Russia; Faculty of Science of Palacký University Olomouc, 17. listopadu 1192/12, 779 00 Olomouc, Czech Republic)

363-NUCLEUS2022_Abstract_Kohoutova_Alena_doc.doc

13:10 Simulated and experimental characteristics of a gas-filled recoil separator DGFRS-II

For further physical and chemical studies of superheavy elements (SHEs), SHE Factory was constructed at FLNR JINR. The facility is based on a new DC-280 heavy-ion accelerator that can deliver 48Ca beams with a projected intensity of 6*1013 ions per second. The first experimental setup of the SHE Factory is a gas-filled recoil separator DGFRS-2 with a QvDhQhQvD magnet configuration. A model of the DGFRS-2 was created using a GEANT4 toolkit. The main methods of trajectory simulations of heavy ions in gaseous media are presented:
Forming of a compound nucleus in the target layer.
Evaporation of several neutrons from an excited nucleus.
Modeling of multiple scattering of ERs in the target and other separator’s media (filling gas, a Mylar window between the separator and detector volumes, pentane in the detector chamber).
Calculation of energy losses in the target and gaseous media.
Modeling of an ERs recharge process in gas.
Calculation of recoil trajectory in the magnetic fields of the separator.
The calculated data agreed well with the experimental data generated in test experiments.

Speaker: Mr Dmitriy Solovyev (FLNR JINR)

nucleus-2022-abstract-Solovyev-DI.docx

13:30 Comparison between elastic scattering of strongly bound α particles and exotic 6He on a 12C target and the effect of the two-neutron halo of 6He

The experimental angular distributions for α-particles elastically
scattered from the 12C nucleus in the energy range of 48.7–386 MeV and
for the 6He+12C nuclear system in the energy range of 5.9–493.8 MeV
have been reanalyzed. Data analysis is performed within the framework
of both the optical model (OM) and the double-folding optical model
(DFOM). In this model, the real part of the potential is generated
using the double-folding procedures based on the effective M3Y
interaction between projectile nucleons and target nucleons, in
addition to an imaginary part of the Woods-Saxon form. Two criteria
are used to observe the nature of 4He and 6He elastically scattered
from 12C and the effect of the two-neutron halo structure of 6He.
Firstly, the extracted potential parameters are utilized for
calculating the reflexion coefficients ηL, which are strongly
related to the angular momentum L. Secondly, the reduction in reaction
cross sections with the projectile’s energy.

Speaker: Ahmed Amer

12:10 → 13:40 Experimental and theoretical studies of nuclear reactions: NR2

Convener: Юрий Чувильский

12:10 NEW MODES OF COLLINEAR CLUSTER TRI-PARTITION OF $^{252}$Cf(sf)

In our previous publications [1–4] we discussed various manifestations of a new decay channel of the low excited heavy nuclei called collinear cluster tri-partition (CCT). In the frame of the essentially modified experimental method, additional linear structures corresponding to the relations M$_1$ $+$ M$_2$ $=$ const and M$_1$ $–$ M$_2$ $=$ const for the masses M1 and M2 of the fission fragments (FFs) from $^{252}$Cf(sf) detected in the opposite spectrometer arms form the rhombic-like configurations with the vertices corresponding to the magic nuclei. The structures are statistically reliable, they are conditioned by a pronounced and complex correlation between the masses of the FFs measured independently. Possible physical scenario standing behind the structures are discussed.

Speaker: Prof. Yuri Pyatkov (JINR & MEPHI)

nucleus-2022-abstract-Pyatkov.docx

12:30 YIELDS AND ENERGY DISTRIBUTIONS OF α-PARTICLES IN SPONTANEOUS TERNARY NUCLEAR FISSION

In [1,2], a virtual mechanism of ternary fission of the nucleus (A, Z) was proposed, which is considered as a two-stage process, when at the first stage an α-particle with kinetic energy $T_{\alpha}$ close to the height of its Coulomb barrier emits from the specified nucleus, with the formation of a virtual state of the intermediate nucleus (A – 4, Z – 2), which at the second stage is involved in binary fission. Part of the energy of the emitted long-ranged α-particle is taken by reducing the heat of fission of the intermediate nucleus (A – 4, Z – 2) by ($T_{\alpha}-Q_{\alpha}$ ), where $Q_{\alpha}$ is the heat of the true α-decay of the nucleus (A, Z). The energy distribution $W_{\alpha f}$ and yield $N_{\alpha}$ of the α-particles, taking into account the proximity of the fission widths of the nuclei (A, Z) and (A – 4, Z – 2) from the configuration (0) of these nuclei with a neck of radius $R_{neck}$ between two fission prefragments, are defined as
$$ W_{\alpha f}= \frac{1}{2\pi} \frac{(\Gamma_{\alpha}^A)^0}{(Q_{\alpha}^A-T_{\alpha})^2}=\omega_{\alpha} \frac{\hbar c \sqrt {2 T_{\alpha}} }{2R_{neck}\sqrt{\mu c^2}}P(T_{\alpha}); N_{\alpha}=\int W_{\alpha f}(T_{\alpha})dT_{\alpha},$$ where $(\Gamma_{\alpha}^A)^0$ is the width of the decay of the parent nucleus from the configuration (0), $P(T_{\alpha})$ is the permeability factor of the Coulomb barrier formed by the sum of the nuclear $V_n(r,\theta)$ and Coulomb $V_C(r,\theta)$ interaction potentials of α-particle and deformed fission fragments , $\omega_{\alpha}$ is the probability of α-particle formation in the parent nucleus, $\mu$ is the reduced mass of ternary fission products. Calculating the permeability factor $P(T_{\alpha})$ of the Coulomb barrier by an α-particle as $P(T_{\alpha})=exp(- \frac {2}{\hbar c }\int_{R_A}^{R} \sqrt {2\mu c^2(V_n(r, \theta)+V_C(r,\theta))-T_{\alpha})} d{r}$, when using the deformed Coulomb potential, Saxon-Woods potential and proximity potential [4] for the nuclear potential, the energy distributions and yields of α-particles for $^{248}Cm$, $^{250}Cf$ and $^{252}Cf$ nuclei are obtained, which are consistent with the experimental energy distributions and yields of α-particles for these nuclei [5 – 6] .

1. S.G. Kadmensky et al. PEPAN 63, 620 (2022)
2. S.G. Kadmensky, L.V. Titova, D.E. Lyubashevsky Phys. At. Nucl. 83, 326 (2020)
3. L.V. Titova, Bulletin MSU. Ser. 3: Physics. Astronomy. № 5, 64 (2021)
4. J. Blocki, J. Randrup, W.J. Swiatecki, C.F. Tsang, Ann. Phys. (N.Y.) 105, 427 (1977)
5. S.Vermote et al., Nucl. Phys. A806, 1 (2008)
6. O.Serot, N.Carjan, C.Wagemans, Eur. Phys. J. A. 8, 187 (2000)

Speaker: Larisa Titova (Voronezh State University)

175-nucleus-2022-abstract-Titova-Kadmensky.docx

13:10 PROBLEMS OF DESCRIPTION OF P-EVEN T-ODD ASYMMETRIES IN NUCLEAR FISSION REACTIONS WITH THE EMISSION OF LIGHT PARTICLES IN THE FRAMEWORK OF THE SEMICLASSICAL APPROACH

In [1–2], the coefficients of P-even T-odd asymmetries in the cross sections for nu-clear fission reactions by cold polarized neutrons with the emission of light particles p were found, expressed in terms of experimental particle count rates p in coincidence with light fission fragments for the directions of polarization vector either along or against the Y axis. For the theoretical description of these coefficients in the case of -particles us-ing the semiclassical method of trajectory calculations, the formula [1] (1) was proposed. Its first term, expressed through the rotation angle , took into account the influence of the Coriolis in-teraction of the spin of a compound fissile system (CFS) rotating around an axis perpendicular to its symmetry axis on the angular distributions of both fission fragments ( ) and -particles ( ). The appearance of the second term in (1) was based on the hypothesis [1] about the change in the angular distribution of -particles under the action of the Coriolis interaction associated with the collective rotation of the CFS around the fission axis, which turns out to be possible when the axial symmetry of the CFS is violated due to taking into ac-count its collective transverse oscillations, in the vicinity of the rupture point. The coefficients calculated in [1] using formula (1), for the positive values of the angles found in the trajectory method, turned out to be in satisfactory agreement with the corresponding ex-perimental coefficients [1] for target nuclei 233U, 235U, 239Pu и 241Pu. Formula (1) can be generalized to the case of emission of evaporative neutrons and -quanta, taking into account the fact that the influence of two types of Coriolis interaction on the angular distribu-tions of these particles can be neglected, since these interactions are small at the moment of emission of evaporative particles due to very large values of the moment of inertia CFS. This leads to the exclusion of the quantity in (1) and the replacement of the angle by the angle . The coefficients calculated using the obtained formula turned out to be in satisfactory agreement with similar experimental coefficients from [2] in the case of the 235U target nucleus, but has opposite signs for the 233U target nucleus. The last result demontrates the need to look for an alternative approach to the description of the coefficients , different from the semiclassical approach.

Speaker: Dmitrii Lyubashevsky (Voronezh state university)

квазиклассический подход.doc

12:10 → 13:50 Intermediate and high energies, heavy ion collisions

Convener: Igor Pshenichnov (INR, Moscow and MIPT)

12:10 Direct photon and neutral meson production results from ALICE experiment

The ALICE experiment at the LHC is dedicated to the study of the hot and dense medium produced in heavy-ion collisions, the so-called quark-gluon plasma (QGP). Neutral meson spectra and direct photon spectra at high $p_{\rm T}$ impose constraints on parton distribution functions in protons and nuclei, and provide information about the transport properties of the QGP. The temperature of the hot fireball created in a heavy-ion collision can be studied via the measurement of low-$p_{\rm T}$ direct photons.

Photons are reconstructed in ALICE with two complementary methods, using the electromagnetic calorimeters or via the reconstruction of e$^+$e$^-$ pairs from conversions in the ALICE detector material using the central tracking system. This approach provides reliable cross checks of results and allows to reduce the statistical and systematic uncertainties of the measurements. In addition, the fraction of direct photons to inclusive photons can be measured with virtual photons (dielectrons) at low $p_{\rm T}$ with different systematic uncertainties.

We report recent results from ALICE on the direct photon and neutral meson measurements in pp, p-Pb, and Pb-Pb collisions and compare them to model calculations.

Speaker: Dmitry Blau (NRC "Kurchatov Institute")

Abstract for Nucleus-2022 gamma pi0.docx

Blau_Nucleus_v5sup.pdf

12:30 Production of Σ0 hyperon and search of Σ0-hypernuclei at LHC with ALICE

The first measurements of the transverse momentum (pT) spectra, integrated yields and mean pT of Σ0 and anti-Σ0 hyperons in pp collisions at s√=7 TeV at the LHC are presented. The Σ0(anti-Σ0) signal is reconstructed via its electromagnetic decay channel Λ (anti-Λ)γ. The Λ (anti-Λ) baryon is reconstructed via its decay into p + π− (anti-p+π+), while the photon is detected by exploiting the unique capability of the ALICE detector to measure low-energy photons via conversion into e+e− pairs in the detector material.
The yield of Σ0 is compared to that of the Λ baryon, which has the same quark content but different isospin. These data contribute to the understanding of hadron production mechanisms and provide a reference for constraining QCD-inspired models and tuning Monte Carlo event generators such as PYTHIA.

In addition, the feasibility of a search for a bound state of proton, neutron and Σ0 (Σ0-hypernuclei 3Σ0H) is presented, based on the luminosities foreseen for the LHC Runs 3 and 4.

Speaker: Alexander Borissov (MIPT (RU))

Borissov-Abstract-Nucleus-2022-v3.pdf

Borissov-Nucleus2022-v4.pdf

12:50 Searches for new physics with ultra-peripheral collisions at the LHC

Ultra-peripheral collisions of heavy ions (UPCs) give a unique opportunity for studies of two-photon interactions in an environment with suppressed hadronic processes and enhanced electromagnetic interactions. Specifically, studies of light-by-light scattering process (LbyL) can provide a new insight on axion-like particles (ALPs) production, which emerge in a number of Standard Model extensions and are proposed as dark matter candidates. LbyL was measured by the ATLAS and CMS collaborations in the mass region above 5 GeV/$c^2$, and there is a possibility for the new ALICE 3 experiment to cover the low mass region, that could possibly explain muon $g-2$ discrepancy observed at the Fermilab.

Precise measurements of the anomalous magnetic moments of leptons can be used to probe effects of physics beyond the Standard Model (BSM), such as production of supersymmetric particles or composite nature of leptons. Sensitivity to BSM physics of the anomalous magnetic moment of the $\tau$-lepton is predicted to be $\sim$280 times higher than that of the muon, but the short lifetime makes it impossible to use conventional measurement methods. UPCs are proposed as an alternative tool, as cross sections of $\tau$ production are sensitive to the anomalous magnetic moment.

In this contribution, the prospects of LbyL measurements, ALP searches and tau g-2 studies with ultra-peripheral collisions at the LHC will be discussed.

Speaker: Nazar Burmasov (Petersburg Nuclear Physics Institute)

nucleus-2022-abstract-nb.docx

nucleus2022_new_physics.pdf

13:10 Probing the hot QCD matter via quarkonia at the next-generation heavy-ion experiment at LHC

Quarkonia represent one of the most valuable probes of the deconfined quark-gluon hot medium since the very first experimental studies with ultrarelativistic heavy-ion collisions. A significant step forward in characterizing the QCD matter via systematic studies of quarkonia production will be performed by the next-generation heavy-ion experiment ALICE 3 [1], a successor of the ongoing ALICE experiment at the Large Hadron Collider. The new advanced detector of ALICE 3 will allow for exploring production of S- and P-state quarkonia at high statistics at low and moderate transverse momenta range. Performance of the ALICE 3 for quarkonia measurements and requirements for the detectors will be discussed in the talk.

1. ALICE Collaboration, Letter of intent for ALICE 3: A next-generation heavy-ion experiment at the LHC. CERN-LHCC-2022-009, LHCC-I-038

Speaker: Yuri Kharlov (Institute for High Energy Physics of NRC Kurchatov Institute (RU))

nucleus-2022-abstract-Kharlov.docx

nucleus-2022-Kharlov_v1.pdf

13:30 Performance of the precise electromagnetic calorimeter ALICE/PHOS and upgrade plans

The photon spectrometer (PHOS) of the ALICE experiment is a high-granularity PbWO4 crystal calorimeter with avalanche photodiode (APD) readout. Its primary physics goal is the measurement of direct photon and neutral meson spectra and correlations in pp, p-A and A-A collisions. PHOS participated in LHC Run 1 (2009-2013) and Run 2 (2015-2018), during which a large amount of physical data were collected in pp, p-Pb and Pb-Pb collisions.

The choice of active material with small Molière radius allows PHOS to operate in a high-multiplicity environment and to reconstruct neutral pions
by two-photon decays up to very high transverse momenta ~60 GeV/c. In order to increase the light yield of the crystals and reduce electronic noise,
PHOS is cooled down and kept at a constant temperature of -25^{o} C. This resulted in excellent energy and position resolutions. Dedicated L0 and L1 triggers were used to increase collected integrated luminosity during data taking.

We will present an overview of the PHOS performance during Runs 1 and 2 and plans for an upgrade for LHC Run 4 and beyond with the aim of improving the time and energy resolution and extending the dynamic range down to low energies. This goal can be achieved by upgrading the photodetectors from APD to multi-pixel photon counters (MPPC), upgrading the front-end electronics and the detector mechanics. The expected improvements of the time and energy resolutions will be presented and the resulting reduction of systematic uncertainties of ongoing analysis and new possibilities will be discussed.

Speaker: Dmitri Peresunko (NRC Kurchatov institute)

nucleus-2022-abstract-PHOS.docx

Nucleus22-Peresunko.pdf

12:10 → 13:50 Nuclear structure: theory and experiment

Convener: Dmitri Eremenko

12:10 POSSIBLE ROTATIONAL STRUCTURE OF $^{13}$C LOW-LYING EXCITED STATES

$^{13}$C is a good example of a “normal” nucleus that is well described in the framework of the shell model. Its level scheme is reliably determined up to excitation energies ~ 10 MeV.
However, some open questions remain regarding the structure of low-lying $^{13}$C states. This leads to increased attention to $^{13}$C so far.
In [1] a hypothesis was put forward about a new type of symmetry in the $^{13}$C structure - D’$_{3h}$ symmetry. Based on this symmetry within the framework of the algebraic cluster model [1] a rotational nature was predicted for low-lying excited states of $^{13}$C and almost all low-lying $^{13}$C states were distributed among 6 rotational bands. Thus, a critical analysis of the available data is required to answer the question about the nature of low-lying excited states of $^{13}$C.
We propose to check the possibility of the existence of these rotational bands based on Modified diffraction model (MDM) analysis. The g.s.-based rotational band proposed in the framework of the algebraic cluster model may exist, since MDM analysis showed that all states of this band have normal, nonincreased root mean square radii. The second rotational band predicted in the framework of the algebraic cluster model, the band based on the 3.09 MeV state, is very interesting and promising, since its first state of this band is the state with a halo. And the question arises about the nature of other states of this band? It is quite natural that the states of one band should have similar features. Is the halo structure preserved for the other members of this band? It should also be noted that all other members of this band are unbound, while 3.09 MeV is bound. Indeed, a preliminary MDM analysis of the existing experimental data on the scattering of light particles showed that the elder members of this band have increased root mean square radius. This result speaks in favor of the possibility of the existence of this rotational band and, possibly, of the halo–like structure of its elder members. The band predicted in the framework of the algebraic cluster model, which contains the 9.90 MeV state, most likely does not exist, since we showed within MDM that the members of this assumed band have different radii. 8.86 MeV has an increased radius, the rest of the states have a non-increased radius. Thus, some of the predicted rotational bands may actually exist. It should be mentioned that negation of at least one rotational band predicted within the D'$_{3h}$ symmetry raises doubts on the applicability of this symmetry to $^{13}$C.

1. R. Bijker, Phys. Rev. Lett. 122, 162501 (2019).

Speaker: Dr Andrey Danilov (NRC Kurchatov Institute)

nucleus-2022-abstract-Danilov.docx

12:30 SIZE ISOMERS IN LIGHT NUCLEI

The size of a nucleus defined by the radius of its nucleon (proton and neutron) density distribution and the proton charge distribution is one of the most fundamental and important nuclear characteristics. Nuclear radius determines the basic properties of nuclei and is a consequence of the fundamental features of the strong interaction.
The development of methods of measuring the radii of nuclei in their short-lived excited states led to discovery of new classes of states, which were named “the size isomers”.
Up to now two groups of the size isomers were identified: the excited states with halos ($^{9}$Be, $^{11}$Be, $^{13}$C, $^{13}$N) and some specific alpha cluster states ($^{11}$B, $^{12}$C, $^{13}$C). All the observed states are diluted, however, some indication to possible existence of more compact than the ground states was obtained as well (in $^{13}$C).
The phenomenon of size isomerism occurred to be not a rare one especially if one takes into account that rotational bands are based on some of such states. The structure of size isomers is related with some new features, e.g., rotating halos, halos in continuum, different types of quasimolecular configurations. Some rudimentary signs of alpha particle condensation (a “ghost“of condensate) were observed (in the Hoyle state of $^{12}$C), however, one cannot speak about confirmation of this ambitious theory.

Speaker: Alla Demyanova (NRC KURCHATOV INSTITUTE)

nucleus-2022-abstract-Demyanova.docx

12:50 STUDY OF EXCITED STATES IN ATOMIC NUCLEI 46Ti AND 45Ti IN REACTIONS WITH 3He BEAM AT 29 MeV

The results of measurements of the angular distributions of deuterons in the 45Sc(3He, d)46Ti reaction are presented, from which the cross sections for population of the ground and excited states in the 46Ti nucleus were determined [1]. The energy of the bombarding 3He particles was 29 MeV.
The measured angular distributions for the excited states in the 46Ti nuclei are compared with the results of other measurements at several values of 3He energy. A comparison of the angular distributions for the ground and excited states of 46Ti with DWBA calculations showed that the pickup of a proton from 3He to the target nucleus mainly results in transfer of 3 or 1 units of angular momentum, which corresponds to the population of 1f7/2 and 2p3/2 shells, respectively. It was shown that rearrangement of nucleons in the unfilled 1f7/2 and 2p3/2 shells leads to excitation of both collective and particle-hole states with different angular momenta. The energy spectra of 46Ti obtained in the experiment were analyzed within the framework of the dinuclear system model [2].
For the 45Sc(3He, t)45Ti reaction, the spectrum of excited states of 45Ti was measured for the first time [3]. Significantly fewer excited states in the resulting 45Ti nucleus are populated compared to 46Ti; moreover, mainly low-lying single-particle states are populated.
The experiments were carried out at the accelerator of the Institute of Nuclear Physics, Řež, Czech Republic.
1. N. K. Skobelev, Yu. E. Penionzhkevich, V. Burjan, and J. Mrázek, Bulletin of the Russian Academy of Sciences: Physics 84, 425 (2020).
2. T.M.Shneidman, G.G.Adamian, N.V.Antonenko, R.V.Jolos, S.-G.Zhou, Phys.Rev. C 92, 034302 (2015).
3. N. K. Skobelev, Yu. E. Penionzhkevich, I. Siváček, T. Issatayev et al., Physics of Particles and Nuclei 53, 382 (2022).

Speaker: Dr Nikolay Skobelev

Study of excitation states 45 Ti AND 46 Ti-abstract.docx

13:10 $^8$He SPECTROSCOPY IN STOPPED PION ABSORPTION REACTION

Level structure of heavy helium isotope $^8$He is studied in the reactions of stopped pion absorption $^9$Be($\pi^-,p$)X, $^{10}$B($\pi^-,pp$)X, $^{11}$B($\pi^-,pd$)X, $^{12}$C($\pi^-,p^3$Нe)X, $^{14}$C($\pi^-,d^4$Нe)X, $^{14}$C($\pi^-,t^3$Нe)X. The experiment was carried out at the LANL with a two-arm semiconductor spectrometer.  The ground and excited states have been observed. The assumption  that the  excited state E$_x \approx $ 3 MeV is a soft dipole mode is made. The states E$_x \approx $ 9.3 MeV, 11.5 MeV, 12.2 MeV  have been observed for the first time. Parameters of excited states have been compared with data of other experimental and theoretical works.

Speaker: Tatiana Leonova

191-nucleus-2022.docx

nucleus-2022-abstract.pdf

13:30 Experimental manifestation of the strong nuclear interaction in the optical spectra of solids

Experimental manifestation of the strong nuclear interaction in the optical spectra of solids
V.G. Plekhanov
Fonoriton Sci. Lab., Garon Ltd, Tallinn 11413, Estonia, vgplekhanov@gmail.com
The primary task amongst other nuclear physics fundamental tasks is experimental measuring of nuclear force interacting between nucleons (protons and neutrons) and their dependence on nucleons' distance in between. The discovery of the neutron by Chadwick in 1932 may be viewed as the birth of the strong nuclear interaction In 1935 Yukawa have tried to develop a theory of nuclear forces. The most important feature Yukawa^{'} forces is they have a small range (~10⁻¹⁵ m). However, up to present time phenomenological Yukawa potential can not be directly verified experimentally. We should remind that the strong nuclear interaction - the heart of Quantum Chromodynamics (QCD) which is the part of the Standard Model (SM). According to SM the nuclear force is a result of the strong force binding quarks to form protons and neutrons [1]. Residual part of it holds protons and neutrons together to form nuclei. There are common place in nuclear and high energy physics that the strong force does not act on leptons.
Our report is devoted to study the strong nuclear interaction via measuring the low - temperature (2 K) photoluminescence spectra of LiH (Eg = 4.992 eV) (without strong interaction in hydrogen nucleus) and LiD (Eg = 5.095 eV) (with strong interaction in deuterium nucleus) single crystals.
The uniqueness of the LiH and LiD compounds is that they differ in only one neutron, i.e. lithium ions, electron and proton are the same for them and, therefore they have the same gravitational, weak and electromagnetic interactions. The additions of a neutron to hydrogen nucleus, generates according to Yukawa, a strong interaction between a proton and a neutron, the effect on which on electron is manifested in the isotope shift (0.103 eV) of the zero - phonon photoluminescence line of free excitons in LiD crystals (see Fig 1 in Ref.2.). The experimental observation of isotope shift (0.103 eV) of the phononless free exciton emission line in LiD crystals is a direct manifestation of the long - range nuclear strong interactions on the leptons [3]. Moreover, we have measured the dependence of the nuclear strong force on the distance between nucleons in deuterium nucleus.
1. D.H. Perkins, Introduction to High Energy Physics (CUP, Cambridge, 2000).
2. V.G. Plekhanov, Phys. - Usp. 62, 947 (2019)
3. V.G. Plekhanov, Atomic Energy 131, 123 (1921) (in Russian).

Speaker: Vladimir Plekhanov (Fonoriton Sci. Lab.)

55-Experimental manifestation of the strong nuclear interaction in the optical spectra of solid1.docx

Desktop.rar

EX.pdf

12:10 → 13:55 Nuclear technology and methods in medicine, radioecology.

12:10 RADIOACTIVE PARTICLES TRANSPORT AND ABSORBED DOSES DISTRIBUTION IN THE RATS’ GASTROINTESTINAL TRACT

The radioactive (“hot”) particles (HP) production can occur in different nuclear accidents. To date, a large amount of scientific data on radiation exposure of humans and other mammals has been accumulated, but information on radiative effect on the gastrointestinal tract (GIT) by HP is not enough.
The aim of the study was to simulate the HP transfer in the gastrointestinal tract (GIT) of laboratory rodents (namely, rats) and estimate doses of internal irradiation. It should be noted that monogastric rodents are widespread in nature and can be used as reference organisms to evaluate the radiative effect on the environment. Besides, their GIT is morphologically similar to the human one.
To study the HP radiative effect on laboratory rodents, the rats of Wistar breed weighing from 200 to 300 g were used. In the experiments the silicate fused radioactive particles gage 80-160 µm got by “uranium”, “three-component” and “rhenium” models were used because their radiation characteristics are similar to ones of instantaneous fission products of 10-15 hours age. At the time of the HP intake in animals, the HP specific activity ranged from 3.7 to 7.4 GBk/g (100-200 MCi/g). Figure 1 shows the experimental data on time-depended radiation for all kinds of HP.
The one-compartmental model of HP transfer was applied to estimate time-dependent activity in rat’s stomach. Then, dose rates in stomach and intestines were evaluated by two calculation techniques:
a) traditional, using simple semiempirical model;
b) more precise one, based on RADAR rat phantom [1].
Dose rates and accumulated doses were received in 1) source localization, i.e. fundus ventriculi; 2) small intestine; 3) thick intestine. In General, the best consistency of accurate and semi-empirical results is achieved at the source localization point. On the periphery, as you would expect, the discrepancy of results is greater. Here doses are many times less.

1. E.N. Denisova, Yu.A. Kurachenko. Med. Phys., No. 2(90), 2021. P. 66-72.

Speaker: Dr Yu.A. Kurachenko

Кураченко2.doc

12:30 DIAGNOSTIC REFERENCE LEVELS IN NUCLEAR MEDICINE IN RUSSIAN FEDERATION

Dear collegues,
Attached is my abstract.

Speakers: Dr Larisa Chipiga (Research Institute of Radiation Hygiene named after P.V. Ramzaev, St. Petersburg, Russia) , Dr Aleksandr Vodovatov (Research Institute of Radiation Hygiene named after P.V. Ramzaev)

DRL in NM.docx

12:50 THE PIPLAN2021 PROTON AND CARBON ION RADIATION THERAPY TREATMENT PLANNING SYSTEM

This paper describes the main features of newest version of the PIPLAN Proton-Carbon Ion Radiation Therapy Treatment Planning System. The PIPLAN 2021 code [1] was assigned for precise Monte Carlo treatment planning for heterogeneous areas, including lung, head and neck location. Three various computer methods are used to modeling the interactions between the proton and carbon ion beam and the patient's anatomy to determine the spatial distribution of the radiation physical and biological dose. The first algorithm is based on the use of the RTS&T 2021 precision radiation transport code system. The RTS&T [1] code (Radiation Transport Simulation and Isotopes Transmutation Calculation) was assigned for detailed Monte Carlo simulation of many particle types (γ, e±, p, n, π±,, , antinucleons, muons, ions and etc.) transport in a complex 3D geometry's with composite materials in the energy range from a fraction eV to 20 TeV and calculation of particle fluences, radiation field functionals and isotopes transmutation problem as well. A direct using of evaluated nuclear data libraries (data-driven model) (ENDF/B, ROSFOND, JENDL, BROND, TENDL etc. - total 14 libraries) to N, d, t,3He,4He particles transport and isotopes transmutation modeling in low and intermediate (E<200 MeV) energy regions is the general idea low-energy part of the RTS&T code. In general, this approach is limited by the available evaluated data to particle kinetic energies up to 20 MeV, with extensions up to 30 MeV or 200 MeV. To generate the output characteristics of secondary particles in NA-interactions in the energy region exceeding 200 MeV, as well as to model acts of inelastic hA- and AA interactions in the entire range of energies under consideration, software implementations of the JQMD model (JAERI Quantum Molecular Dynamics) were used and the cascade-exciton model (CASCADE), including the generation of nuclear fragments in both the post-cascade and fast stages of the reaction (up to the complete break-up of the nucleus). In the process of transport simulation, the decay processes of metastable fragments with the subsequent transport of decay products were considered.The second and third algorithms are based on the original Bortfeld’s [2] and Ulmer’s [3] methods for primary proton beam and adapted these algorithms for primary carbon ion beam.

1. I.I. Degtyarev, F.N. Novoskoltsev, O.A. Liashenko, E.V. Gulina, L.V. Morozova, The RTS&T-2014 code status, Nuclear Energy and Technology, v.1, Issue 3, Nov. 2015, p.222-225.
2. T. Bortfeld, An analytical approximation of the Bragg curve for therapeutic proton beams, Med. Phys., 24(12), Dec. 1997. p. 2024-2033.
3. W. Ulmer, E. Matsinos, Theoretical methods for the calculation of Bragg curves and 3D distributions of proton beams, The European Physical Journal Special Topics, v. 190, p.1–81, 2010.

Speaker: Dr Igor Degtyarev

nucleus-2022-abstract-Degtyarev.docx

13:10 New approaches to the modernization of technologies for radiation sterilization of bioimplants

Modern requirements for the quality of bioimplants combine the need to ensure not only the necessary osteoinductive potential, adequate structure and mechanical strength, but also guarantees the safety of the recipient due to the high level of sterility of the plastic material.
Among the currently used technologies for the sterilization of biomaterials, radiation exposures occupy an increasing volume [1]. However, the presence of pronounced dose-dependent side effects that can lead to deterioration of all of the above vital properties and characteristics of bone implants determines the need for further improvement of radiation technologies.
One of the promising solutions is the development of combined technologies that combine, along with radiation treatment, other types of physico-chemical effects with a pronounced resultant synergism of sterilization action. As the author's research has shown, one of such promising combinations is two-stage treatment (ozone + radiation) [2]. Further development and improvement of the new technology is carried out in several directions. Firstly, the optimization of the impact parameters at each of the stages. Secondly, the choice of optimal sources (ozone, radiation) effects to ensure the quality of manufactured bone implants, including the characteristics of the surface layer of bone samples [3,4] (relief, microarchitectonics, mechanical characteristics, elemental composition, etc.).
This research has been supported by the Interdisciplinary Scientific and Educational School of Moscow University «Photonic and Quantum technologies. Digital medicine».

1. V.V.Rozanov, I.V.Matveichuk . Clinical Medicine Almanac, 47, 7. (2019).
2. I.V.Matveichuk, V.V.Rozanov, I.K.Gordonova et al. Patent of Russian Federation № 26
   30464, (29.07.2016).
3. V.V.Krasnov, I.V.Matveichuk, V.V.Rozanov et al. // Genes and Cells, V. XIV, Suppl. P.125.(2019).
4. Chernyaev A.P., Rozanov V.V., Beklemishev M.K., et al. // Bull. Russ. Acad. Sci. Phys.. 84.11. (2020).

Speaker: Prof. Vladimir Rozanov (Lomonosov Moscow State University)

Тезисы-Ядро-2022-1.docx

13:30 THE STATUS OF FOOD IRRADIATION RESEARCH IN LOMONOSOV MOSCOW STATE UNIVERSITY

Radiation technologies are commonly used in different areas, such as medicine, in treatment of tumors, radioecology, to ensure radiation safety of the natural environment, and agriculture, to combat with pests and stimulate the growth of crops. Moscow State University (MSU) is currently focusing on five aspects of research in food irradiation.
Our researchers are particularly involved in the development of irradiation technology with accelerated electrons. Such a focus is determined by economic demand in view of the fact that electron accelerators have proved to be more efficient in terms of dose rate and processing speed, and much safer compared to radioisotopes. Moreover, it is possible to determine the irradiation depth by varying electron beam energy. However, it is still unclear how to achieve a consistent dose uniformity in objects of different geometry and texture. To solve this problem we have developed and tested a dose uniformity method using aluminium modifiers placed between the accelerator output and the treated object. Researchers of MSU are now improving this method to ensure the 100 % irradiation dose uniformity in objects with the linear dimension of up to 8 cm.
Another area of MSU research is the reconstruction of electron beam spectrum using experimental depth dose distributions in phantoms developed specifically for simulation and measuring dose values. Knowing the spectrum of industrial accelerator allows to calculate depth dose distribution in the objects of different geometry and precisely estimate the dose uniformity throughout the treated food item. In search of optimal irradiation treatment parameters, our researchers are studying the effect of the dose value and rate, as well as type of irradiation on microbiological and chemical composition of a range of foods. The data obtained during the research can be used for the development of state irradiation guidelines. One more area of the research is detecting the fact of foodstuff irradiation by means of gas chromatography to identify organic volatile compounds, which show that some irradiation treatment has been performed on the item. Also the fluorescent fingerprinting express method is being assessed as a potential strategy to prove the fact of irradiation treatment. To address the needs of agriculture our university is studying the impact of pre-seeding irradiation treatment on crops infected with different fungi to increase the yield and its phytosanitary safety.

Speaker: Dr Ulyana Bliznyuk (Lomonosov Moscow State University)

14:00 → 15:00 Lunch

15:00 → 16:40 Applications of nuclear methods in science and technology

Convener: Nikolay Novikov (Skobeltsyn Institute of Nuclear Physics Moscow State University, Moscow, Russia)

15:00 TARGET DESIGN FOR EXPERIMENTAL INVESTIGATION OF ADS WITH PROTON AND LIGHT ION BEAMS

A particle accelerator coupled with a subcritical fission reactor (accelerator driven system - ADS) can realize a safe, clean and efficient source of energy. We showed that in spite of the majority’s opinion with respect to the optimal beam for ADS (considered to be proton with energy 1-1.5 GeV) light ion beams at lower energies are more efficient [1-3]. Aspects related with the core structure and composition, the optimal value of the criticality coefficient keff, the particle beam and the accelerator type were analyzed. The larger pitch to diameter ratio possible to achieve in ADS (~2 for a core cooled with lead or lead bismuth eutectic - LBE) allows to accommodate higher power densities, keeping the coolant velocity below 2 m/s in order to minimize the corrosion effects on the cladding and structural materials. The role of a Be converter with large dimensions (radius 10-20 cm, length 100-120 cm) is emphasized. In the presence of a long Be converter a beam of 7Li with energy 0.2 AGeV is equivalent from the point of view of the net power produced with a beam of 1 GeV proton, and a beam of 0.25 AGeV 7Li is equivalent with a beam of 1.5 GeV protons. This allows to obtain the same net power with a 2.5 times shorter accelerator with lower cost for the power plant building and maintenance. The apparition of a tail towards thermal energy in the neutron spectrum allows to obtain the needed value of the criticality coefficient keff in a given geometry with a lower enrichment, increases the breeding capability of the core and ensures a deeper burning of the actinides in one cycle. Until 25 % of the actinides can be fissioned in one cycle in ADS with Be converter in comparison with 6-7 % that can be achieved in a fast reactor. The analysis of the power evolution after beam stopping and the investigation of possible insertions of positive reactivity during transients concluded that metallic fuel allows a core with keff 0.988, when fuels with melting temperature higher than the clad (as oxide, carbide, nitride) needs a lower value of 0.985 for keff. The maximum energy gain of protons is obtained at 1.5 GeV when they are accelerated in a linac (G ~14), and at lower energy (0.75-1 GeV) when a cyclotron is used. In both situations ion beams starting with 4He realize higher energy gain than protons. Ion beams offer the possibility to obtain energy gain from 25 (with 0.25AGeV 7Li beam) to 45 (with 0.75 AGeV 16O and 20Ne beam).
A proposal for the design of a target dedicated to the experimental study is presented. The design of the experimental target must reproduce at a small scale the situation in a real ADS. The interest is to determine the minimal dimensions and minimal amount of fuel necessary for a correct reproduction of the ratio of the energy released (amount of fissions) produced with proton and ion beams. Two designs are analyzed. In the first, the target consists of rods from enriched U (15 % 235U) with diameter 2 cm and length 120 cm, distributed in 6 layers (~200 rods) inside a cylinder from Pb with length 150 cm and radius 70 cm. The central part of cylinder is empty, allowing the placement of different converters. In the second variant the rods are placed in a graphite target, surrounded by a 10 cm Pb blanket. Due to the softer neutron spectrum, the use of graphite target allows to diminish significantly the number of fuel rods (~20 rods with 15 % 235U).

References:
1. M. M. Paraipan, A. A. Baldin, E. G. Baldina, S. I. Tyutyunnikov, EPJ proceedings MMCP2017, 173 (2017).
2. M. M. Paraipan, V. M. Javadova, S. I. Tyutyunnikov, Prog. Nucl. En. 120 (2020).
3. M. M. Paraipan, I. A. Kryachko, V. M. Javadova, E. Levterova, S. I. Tyutyunnikov, Phys. Part. Nucl. Lett. 19, 2 (2022).

Speaker: Mihaela Paraipan

AbstractNucleus2022.docx

15:20 Estimation of the degree of agreement of empirical random vectors using central moment functions

Estimation of the degree of agreement of empirical random vectors using central moment functions.

Rabotkin V. A., Bliznyakov N.M., Vakhtel V.M., Kostomakha D.E.
Voronezh State University, Voronezh, Russia
E-mail: vakhtel@phys.vsu.ru

A methodology for estimating the degree of agreement M of empirical random vectors (RV):ν(k)=〖(ν〗0,ν_1,…,ν_l) of frequenciesν_i (k=i) of counts k of registered particles by samples of small volume
∑_0^l▒〖ν_i=n<20〗,0≤ν_i≤n
and average ( k) ̅<5 was developed.
The degree of agreement of the vectors is estimated by the test statistics of the closeness of the projections of the fractional order functions 1<S of the central moments μ(ν(k),S) RV– ν:
μ(ν,S)=1/(n-1) ∑_1^l▒〖(k_i-k ̅ )^S=Re(S,μ(.)) 〗+i∙Im(S,μ(.)),i^2=-1,
Where Re(.) and Im(.) is real and imaginary components of the central moments function 1<S. As a test statistic to estimate the agreement of projections μ(S) there was proposed a metric
Φ=∑(S_0=0)^S▒〖(((Re(μ_(1,g) )-Re(μ_(1,h) )))/((Re(μ_(1,g) )+Re(μ_(1,h) )) ))i^2+(((Im(μ(1,g) )-Im(μ_(1,h) )))/((Im(μ_(1,g) )+Im(μ_(1,h) )) ))_i^2 〗∙
∙1/(S_m-S_0 )
The methodology is based on the mutual one-to-one correspondence of the random vector ν(.)=〖(ν〗_0,ν_1,…,ν_l),∑_0^l▒〖ν_i=n<20〗,ν_i (k=j), in the sample and the complex function of fractional order 1<S_0<S_m≤5 of central moment of vector ν(.).

References
Bliznyakov N. M., Vakhtel V. M., Kostomakha D. E., Rabotkin V. A., "Modern methods of the theory of functions and related problems", Proceedings of an international conference, Voronezh: -VSU. 2021. p. 55-57.

Speakers: Mr Victor Vakhtel (Voronezh State University) , Mr Daniil Kostomakha (Voronezh State University)

Estimation of the degree.docx

15:30 Method for processing and analysis of homogeneity of large sets of small-volume samples of low-intensity radiation streams

Method for processing and analysis of homogeneity of large sets of small-volume samples of low-intensity radiation streams.

Rabotkin V. A., Bliznyakov N.M., Vakhtel V.M., Kostomakha D.E.
Voronezh State University, Voronezh, Russia
E-mail: vakhtel@phys.vsu.ru

A method for processing and analyzing sequences of samples of variation series of values of identifiers I(ν(.)) of random vectors (RV) - ν for their corresponding samples of small volume n≤20 of counts k_i=0;1;2… of registered particles was proposed. The identifier I(ν(.)) is a functional in the form of a scalar product RV ν(.)=〖(ν〗0,ν_1,…,ν_l) of frequencies ν_i (k=i) of values of counts k_i in the sample
∑_0^l▒〖ν_i=n<20: I(ν)=I(ν|a)=(νa)=ν_0 a_0+⋯+〗 ν_l a_l
where a=〖(a〗_0,…,a_l) – is not a randomly given vector. For a given number M of vectors ν(.) the frequency distribution of I(ν) values represents sequences of ordered groups of peaks formed by:
similar in components ν_i RV
of homogeneous peaks formed by homogeneous RVs.
To evaluate the homogeneity of RV and peaks, it was proposed a test statistic G and a criterion of agreement based on the metric
G=1/q [∑(l=1)^l▒〖[(x_im-x_ir )/(x_im+x_ir )^2]〗]^(1/2),0≤G≤1.
It was shown that the homogeneity estimation of peaks considered also as random vectors m and rM_(1,m),M_(2,m),…,M_(l,m);M_(1,r),M_(2,r),…,M_(l,r) can be performed by the degree of their collinearity |M_m | |M_l |^(-1)∙M_m∙M_l=cosθ, where θ-is the angle between vectors and equality of |M_m |=|M_r | modules.
The proposed method allows identifying combinatorial types of RV, predicting frequencies of their realization 1<M_j and peaks formed by them - also random vectors M_jm,…,M_qmwith
∑l^q▒〖M(j,m)<10.〗
The method is effective at n<20; average k ̅<5.

References
BliznyakovN.M., VakhtelV.M., KostomakhaD.E., RabotkinV.A. VoronezhWinterMathematicalSchool. Voronezh: -VSU PublishingHouse 2022. p. 27-33.

Speaker: Mr Victor Vakhtel (Voronezh State University)

Method for processing and analysis.docx

15:40 THERMOLUMINESCENCE TRAPPING PARAMETERS OF IRRADIATED K-FELDSPAR

Isothermal decay of TL glow curve of the irradiated K-feldspars has been investigated at an ambient temperature. A suggested procedure enables the isolation of peaks at the low-temperature region of the TL glow curve. An analysis of the values of the symmetry factor suggests that bimolecular mechanisms are responsible for the kinetics of decay processes, as the values of parameter µ [1] vary around 0.52. The values of the calculated activation energy do not show systematic correlation with the temperature at the investigated temperature region of TL glow curve. The frequency factor values of the isolated peaks change within the physically meaningful figures (within the order of 109 to 1013s-1) and in good agreement with the literature [1]. ESR and TL investigations revealed that [2], when feldspars such as microcline and albite are irradiated at liquid nitrogen temperature, both Al-Oh+ and a hydrogen radicals are formed. As soon as the temperature of the samples rises to room temperature, the hydrogen radical eliminates completely and Al-Oh + -Al centers appear. Thermal annealing at 1000 ° C leads to the formation of two new hydrogen radicals which are relatively stable even at room temperature. It has been suggested that they could act as killers for Al-Oh + -Al centers in both feldspars which might be the case in the current situation.

References
[1] R. Chen, V. Pagonis, and J. L. Lawless, “Evaluated thermoluminescence trapping parameters-What do they really mean?,” Radiat. Meas., vol. 91, pp. 21–27, 2016, doi: 10.1016/j.radmeas.2016.04.006.
[2] T. Hashimoto, E. Nishiyama, and Y. Yanagawa, “Radiation-induced luminescence and hydrogen radical formation associated with thermal annealing treatments on feldspars,” J. Radioanal. Nucl. Chem., vol. 255, no. 1, pp. 81–85, 2003, doi: 10.1023/A:1022275630127.

Speaker: Sahib Mammadov (Institute of Radiation Problems, Azerbaijan National Academy of Sciences)

nucleus-2022-abstract_TL parameters.docx

16:00 Simple explanation of the experimental 57Fe Mӧssbauer isomer shift of iron compounds

According to the existing concept, an increase in electron density on 57Fe nucleus must lead to a decrease in Mӧssbauer isomer shift (IS). The rise of oxidation state of iron (escape of electrons from the valence shell) usually leads to the decrease in IS, which is explained by the shielding effects.
We suggest applying the approach of the valence shell hybridization to explain the regularities of the IS change [1]. It is easy to show that two electrons on 4s-orbital create the electron density at the iron nucleus, which is equivalent to the density created by the full set of fully filled 4s4pn3dm-hybridized orbitals:
|ψ_s (0)|^2=∑(i=1)^(1+n+m)▒|(sp^n ⅆ^m)^((i) ) (0)|^2 ,
where n = 0…3 and m = 0…5 are the numbers of the 4p and 3d-orbitals involved in the hybridization. Using this property, we can suggest that the directional chemical bonds, which iron cation establishes with surrounding anions, influence on the IS; this influence being independent on the number of the bonds. Assuming that the IS is proportional to the average bond length, we can explain the observed experimental dependencies. At the same time, d and p-electrons do not create a density on the nucleus. But they affect the ionic radius of the iron ion and, consequently, affect the interatomic distances. Moreover, we concluded that the electron shell of each anion of the iron polyhedron can make noticeable additional contribution to the electron density at the iron nucleus. This makes it possible to explain the dependence of the IS on the iron coordination number.

Speaker: Sergey Dedushenko (Lyalin Pereulok 24/26-43, Moscow 101000, Russia)

nucleus-2022-abstract.docx

16:20 SEARCH CRITERIA FOR MINERAL DEPOSITS IN THE ZONES OF MODERN AND ANCIENT VOLCANISM ON URANIUM AND THORIUM AND THEIR FISSION PRODUCTS

A.M. Yafyasov1, F.F. Valiev1, I.R. Makarova2 S.A. Gorobets2,
V.O. Sergeev2, N.A. Sukhanov, D.K. Makarov3
makarova_i_r@mail.ru
1 - St. Petersburg State University, 2 - PETROFIZIK LLC

In the work, by the method of gamma - spectroscopy [1,2], new data are presented on the deep recharge of the Nizhnechutinsk oil field by ascending gases and hydrotherms with different elemental composition. It has been established that formation waters, as well as oils, are enriched in As, Br, Ba, Re, Ir, Au, REE in the fluid replenishment zones. In this case, the greatest differences relate to the distribution of uranium and thorium over the area of the deposit and over the underlying oil reservoirs.
The results of the studies indicate the overlap and coexistence of deposits of hydrocarbons and ore minerals in the area of ancient volcanism, while the criteria for the influence of the manifestation of deep processes are both the well-known ratios of uranium and thorium (U/Th and/or Th/U) and the established we determined the values of the ratios Th/Ba, Mo/U, Ba/Mo.
The elements Ba and Mo are fission products of uranium and thorium. In this regard, we assume other types of mineralization, associated not with the release of magmas of different composition and post volcanic hydrotherms, but with known exhalation mineralization. According to our ideas, this type of mineralization is accompanied by a constant emanation of radioactive elements U, Th and elements of their radioactive decay along the zones of development of modern and paleovolcanic formations. At the same time, oils in the Upper Devonian deposits are enriched in a number of elements, the associations of which depend on the temperature of the ascending gas flows. Taking into account the results obtained, the search for deposits of solid minerals and hydrocarbons is carried out not only in terms of U / Th, but also according to the new criteria we have established - certain values of the ratios Th / Ba, Mo / U, Ba / Mo in the composition of rocks and accumulations of hydrocarbons.

Literature

1.Makarova I.R., Laptev N.N., Gorobets S.A., Valiev F.F., Yafyasov A.M., Sergeev V.O., Zippa A.I., Sukhanov N.A., Makarov D. .K., Grishkanich AS/ Application of methods of gamma spectroscopy and IR spectroscopy for the purposes of prospecting geology. Georesources, 2021, No. 1. – P.17 – 29.
2. Yafyasov A.M., Makarova I.R., Valiev F.F, Laptev N.N., Gorobets S.A., Sergeev V.O. / The application of gamma-spectrometry with a germanium detector for oil and ore geology // Bulletin of the Russian Academy of Sciences : Physics, 8 no. - T. 86. - 2022 (in print).

Speaker: Adil Yafyasov (Spbgu)

15:00 → 16:40 Experimental and theoretical studies of nuclear reactions: NR1 Experiment neutrons

Convener: Yuri Kopatch (Joint Institute for Nuclear Research (JINR), Dubna, Russia)

15:00 RESULTS OF SIMULATION OF TOTAL AND DIFFERENTIAL CROSS SECTIONS FOR 236U FISSION BY NEUTRONS WITH ENERGY UP TO 200 MeV

In [1], it was rightly noted that “nuclear fission remains the most complex topic in applied nuclear physics”. The current state of the theory based on the model of transition states at fission barriers does not allow one to reproduce the fission cross section of a nucleus by neutrons as a function of their energy without using a significant number of fitting parameters. This is partly due to the lack of information about the spectra of transition states. In our opinion [2,3], the understanding of the fission mechanism can be improved by using data on the angular distribution of fragments or, in other words, on the ratio of the differential fission cross section to the total one. The idea is that the angular distribution of fragments is determined by the distribution of the fission probability over the projection K of the nuclear spin on the axis of deformation on a barrier, which in turn depends on what values of K characterize the rotational bands of transition states on the barrier. Thus, the angular distribution of fragments can provide important information about the spectrum of transition states.
Previously, we analyzed data on fission cross sections and angular distributions of fission fragments in the reactions 237Np(n,f) [3] and 240Pu(n,f) [2]. The present work is devoted to the reaction of 236U(n,f). The parameters of the fission barriers taken from [1] were slightly changed, which made it possible to reproduce, using the TALYS-1.9 program [4], the energy dependence of the total fission cross section in the range of incident neutron energy from 0.5 to 120 MeV. Using a modified version of the same program gives a good description of the angular anisotropy W(0º)/W(90º) of the fission fragments within the statistical model of the probability distribution of fission over the number K in a wide range from 2.5 to 300 MeV. Of particular interest is the low-energy region from 0.5 to 2.5 MeV, in which the energy behavior of angular anisotropy may be related to the structure of the transition state spectrum at the 237U fission barrier.

1. R. Capote et al. Nucl. Data Sheets 110, 3107 (2009).
2. A. S. Vorobyev et al., JETP Lett. 112, 323 (2020).
3. A. L. Barabanov et al.. EPJ Web Conf. 256, 00003 (2021).
4. A. J. Koning, S. Hilaire, M. C. Duijvestijn. Proc. Int. Conf. on Nuclear Data for Science and Technology (2007, Nice, France); EDP Sciences. 2008. P.211.

Speaker: Alexey Barabanov (National Research Centre "Kurchatov Institute")

Barabanov_et_al_Abstract_Nucl-2022.docx

15:20 Prompt fission neutrons investigation at IREN in resonance neutron energy range

Sh. Zeynalov, O. Sidorova1
Joint Institute for Nuclear Research, 141980, Dubna Moscow region Russia
1Dubna State University

Investigations of prompt fission neutron emission are of importance in understanding the fission process in general and the sharing of excitation energy among the fission fragments in particular. Experimental activities at JINR on prompt fission neutron (PFN) emission are underway for more than 20 year. Main focus lies on investigations of prompt neutron emission from the reactions 252Cf (sf) and 235U(n,f) carried out in JINR and EC-JRC-IRMM in the region of the resolved resonances. For the last reaction strong fluctuations of fission fragment mass and the mean total kinetic energy distributions have been observed as a function of incident neutron energy [1, 2]. In addition fluctuations of prompt neutron multiplicities were also observed [3]. The goal of the present study is to verify the current knowledge of prompt neutron multiplicity fluctuations and to study correlations with fission fragment properties. Recent measurement of PFN multiplicity in resonance neutron induced fission of 235U(n,f) reaction reveal surprising result, stimulated us to investigate the PFN multiplicity at IREN with new high efficiency experimental setup.

References
1. Zeinalov Sh.S., Florek M., Furman W.I., Kriatchkov V.A., Zamyatnin Yu. S., Neutron energy dependence of 235U(n,f) mass and TKE distributions around 8.77 eV resonance VII International Seminar on Interaction of Neutrons with Nuclear – Dubna: JINR, -1999. -E3-1999-212. –P. 258-262.
2. F.-J. Hambsch, H.-H. Knitter, C. Budtz-Jorgensen, and J.P. Theobald, Fission mode fluctuation in the resonances of 235U(n,f), Nuclear Physics A -1989. -Vol. 491. –P. 56 – 90.
3. R.E. Howe, T.W. Phillips, C.D. Bowman, Phys. Rev. C 13, 195 (1976)

Speaker: Dr Shakir Zeynalov (JINR)

15:40 PROMPT FISSION NEUTRON SPECTRA OF 235U AND 239PU

Pre-fission neutrons influence the observed prompt fission neutron spectra (PFNS), TKE, average number of prompt fission neutrons, (n,F) and (n,xn) reaction cross sections. Though pre-fission neutrons in 235U(n,F) were first observed around En~14 MeV [1] and then at En~7 MeV [2], only now measured data base [3-6] allows to demonstrate the complex influence of fissility of nuclides 236U and 240Pu on the PFNS shape. The model parameters are fixed at thermal neutron energy [7] and the renormalized for the TKE measured data.
The PFNS shapes at En ~6-7 MeV are strongly correlated with nuclide fissilities in 235U(n,xnf) and 239Pu(n,xnf) reactions and competition of (n,xnX) reactions. Calculated exclusive (n,nγ), (n,2n)1,2 and (n,nf)1 pre-fission neutrons spectra allow to demonstrate that the amplitude of (n,nf) spectra is the largest for 235U(n,F) at En ~6.5 MeV (Fig.1) while for 239Pu(n,F) at En ~6.0 MeV (Fig. 2). When (n,nf) reaction competes only with (n,nγ) reaction, the pre-FNS shapes are rather similar (En ~ 5.5 MeV), though the contribution of (n,nf)1 is much higher in case of 235U(n,F) reaction. When the (n,2n) reaction channel opens, the pre-FNS shapes reveal drastic influence of (n,2n)1 and (n,2n)2 neutron spectra. The fig. 1 demonstrates partials for 235U(n, F) reaction, the numerical data [8] are compatible with data [4,5]. The fig. 2 demonstrates partials for 239Pu(n, F) reaction, while the data [3-6] are compatible with predicted (n,xnf) contributions [9]. The lower curves and data points show the partitioning of the PFNS into the (n, f), (n,nf) and (n,nf)1 contributions.
1. Yu.A. Vasil’ev, Yu.S. Zamyatnin et al., Soviet Physics JETP, 11, 483 (1960).
2. A. Bertin, R. Bois, J. Frehaut 3d All Union Conf.on Neutron Phys.,Kiev,9-13 Jun 1975, Vol.4, p.303 (1975).
3. P. Marini, J. Taieb, B. Laurent, et al., Phys. Rev. C 101, 044614 (2020).
4. K.J. Kelly et al., Eur. Phys. Journ. Web of Conf., 2020, v. 239, 05010.
5. K.J. Kelly, M. Devlin, J.A. Gomez, et al., LA-UR-18-30526, 2018.
6. K. J. Kelly, M. Devlin J.M. O’Donnel et al, Phys. Rev. C 102, 034615(2020).
7. V.M. Maslov, N.A. Tetereva, V.G. Pronyaev et al., Atomic Energy, 108, 432 (2010)
8. V.M. Maslov, N.V. Kornilov, A.B. Kagalenko et al., Nucl. Phys. A 760, 274 (2005), https://www-nds.iaea.org/minskact/data/92235f18.txt.
9. V.M. Maslov, Atomic Energy, 103, No. 2, 633 (2007)

Speaker: Vladimir Maslov

mvm59nucleus-2022f.docx

mvm59nucleus-2022f.pdf

mvmNucl2022+.pdf

u23565.WMF

u23565.WMF

16:10 THE METHOD AND SET UP FOR THE MEASUREMENT OF DELAYED NEUTRON TEMPORAL CHARACTERISTICS FOR THE FISSION OF HEAVY NUCLEI IN THE COMPLEX PRIMARY NEUTRON FIELDS

Present work is dedicated to the description of the set-up designed for precise measurements of the energy dependence of aggregate delayed neutron characteristics in the energy range of primary neutrons from thermal to 20 MeV. The set-up constructed on the base of Tandem-3M accelerator of SSC RF – IPPE consisted of high-efficiency neutron detector, spectrometer of primary neutrons, pneumatic transport system of the sample under investigation, experimental control and data acquisition system. Special emphasis is made to study the influence of the primary neutron flux on performance characteristics of the neutron detector and to the measurements of the primary neutron spectra generated from the reaction D(d,n) on the solid neutron target. The results of measurements of delayed neutron relative abundances and half-lives are presented for the fission of 235U by the neutrons in energy range from 0.42 to 8 MeV, including insufficiently known range from 4 to 8 MeV.

Speaker: Mr Dmitrii Gremyachkin (JSC SSC RF-IPPE)

Method and set up.docx

15:00 → 16:30 Experimental and theoretical studies of nuclear reactions: NR2

Convener: Alla Demyanova (NRC KURCHATOV INSTITUTE)

15:00 Study of the 16O(alpha, alpha)16O(3–) and 15N(alpha, t)16O(3–) reactions mechanism at E_alpha = 30.3 MeV

The study of the differential cross sections angular dependence of the reactions 16O(alpha, alpha) [ 1 ] and 15N(alpha, t)16O(3–) [2] at E_alpha = 30.3 MeV was carried out. Both magnitude and shape of the measured cross sections and large value of E3 transition between the ground and 3– level of 16O nucleus justify the use of CCBA formalism, when both couple channels method (CC) and DWBA are combined (FRESCO [3]) as well as the compound nucleus (CN) mechanism (TALYS [4]) in the theoretical analysis. The strength of coupling factors were introduced from the experimental reduced transition probability B(E3). The exchange of 12С cluster with summation over all states allowed by the selection rules for transfer mechanism at both reactions and proton stripping for the (alpha, t)-reaction were taking into account. The spectroscopic amplitudes are obtained in the shell model. The calculated angular distributions, together with the experimental ones, are shown in figs. It can be seen that in (alpha, alpha')-scattering, the cross section is determined by collective excitation in the front hemisphere and by 12С exchange at large angles. The СN contribution is not noticeable. In the reaction (alpha, t), the main contribution is made by the CN mechanism, else the contribution of the proton stripping is noticeable at forward hemisphere. The 12C exchange mechanism is important at theta_t > 90\circ. The performed analysis showed that the calculated cross sections of both reactions agree with the experimental one without introducing normalization factors only when all considered mechanisms are taken into account.

1. A.V. Ignatenko, V. M. Lebedev, N. V. Orlova et al., Phys. Atom. Nucl. 59, 565 (1996).
2. A.V. Ignatenko, V. M. Lebedev, N. V. Orlova et al., Phys. Atom. Nucl. 61, 1 (1998).
3. J. Thompson, Comp. Phys. Rep. 7, 167 (1988); http:// www.fresco.org.uk.
4. J. Koning, S. Hilaire, and M. C. Duijvestijn, TALYS: AIP Conf. Proc. 769, 1154 (2005).

Speaker: Natali Zelenskaya (Lomonosov Moscow State University, Scobeltsyn Institute of Nuclear Physics)

Тезис 16О_1.docx

15:30 Study of muon catalyzed 3Hed Fusion

The thermonuclear reaction $d({}^3\!He,\alpha)p$ is a very rich playground to study various phenomena in different fields of science. Astrophysicists use data of the cross section to build and tune a theory of primordial nucleosynthesis. Most nuclear reactions data doesn’t contain energy dependencies below several keV, the most interesting region for astrophysics.
From a practical point of view, the reaction is extremely efficient in energy generation. While producing 18.3 MeV worth of energy, one of the highest energy outputs among nuclear reactions, it doesn’t contain nor produce radioactive elements. It makes possible the construction of the safest and efficient thermonuclear reactor.
The use of muons expands studies even more. It makes possible to investigate the reaction at extremely low energy (several eV) that has never been done before. Bombarding a gas mixture of $^3\!He$ and $D_2$ ($H\!D$) with energetic muons results in the formation of exotic muonic molecules such as $^3\!He\mu d$. It was theoretically shown [1] that $^3\!Hed$ fusion can occur in this formation.
The experiment, aimed to investigate muon catalyzed $^3\!Hed$ fusion, is being carried out at PSI (Switzerland) by the PNPI group (Gatchina, Russia). It enables the study of processes involving mesomolecules.
The experimental setup, adopted from the previous experiment MuSun [2], includes the cryogenic TPC, muon beam detectors, kicker and detection system of electrons coming from muon decays. The kicker allows muons to enter the fiducial volume only one by one. The data collected enables to determine a muon stop position, detect tracks of electrons created via the muon decay as well as tracks of fusion products. Information about the energy of each particle is also obtained.
The formation rates of the $d\mu d$ and $^3\!He\mu d$ molecules, the probability of the muon transfer from $\mu d^*$ to $\mu d$, the upper limit for the “effective” $^3\!He\mu d$ fusion decay rate, yields of $^3\!He\mu d$ molecules have been obtained and presented.

1. M.P. Faifman and L.I. Men'shikov, Hyperfine Interact. 119, 127 (1999).
2. V.A. Ganzha et al., PNPI Main Scientific Activities HEPD 2007–2012, 106 (2013).

Speaker: Mr I. Solovyev (NRC Kurchatov Institute PNPI)

54-nucleus_2022_I_Solovyev.docx

Solovyev_Ivan_Nucleus 2022.pdf

15:50 THUNDERSTORM FLASHES AS THE MECHANISM OF 14C RADIOISOTOPE GENERATION

An atmospheric production of 14C radioisotope goes by the 14N(n,p)14C reaction under cosmogenic fluxes and this process is considered as the main source of radiocarbon creation which rate of accumulation is evaluated as ~ 6.6 kg per year. An exclusively opportunities of dating based on the analysis of 14C concentration in the very old and ancient organic samples led to the discovery of short-term secular variation of radiocarbon in tree rings 1 and to the hypothesis of 14C generation under thunderstorms flashes. The nature of the lightning phenomena in fact is connected with the development of electron avalanche in the strong atmospheric electric fields (~ 300 kV/m and more) 2. The very fast electron avalanche growth in the cloud electric fields ensures the phenomenon of terrestrial $\gamma$-ray bursts [2,3]. These energetic γ-rays generate the photonuclear reactions on atmospheric isotopes (with significant yield for hard photons $E_{\gamma}$ = 20-60 MeV) as 14N$(\gamma ,n)$13N, 16O$(\gamma ,n)$15O, 40Ar$(\gamma ,n)$39Ar. An increase of neutron flux causes the next series of $(n,\gamma)$, (n,a), (n,p)-reaction and the 14N(n,p)14C is the top important for dating problem. For evaluating of the radiocarbon generation under thunderstorm conditions (and creation of another atmospheric isotopes too) it was proposed the model (realized in the spherical-layer geometry). The calculation were made at the several altitudes of the lower part of the atmosphere at the altitudes from 1 up to 15 km (covering the possible heights of detected lighting) [4,5]. Decrease of the atmospheric densities at increase of the altitude is critical for electron avalanche evolution and is included in the model. It was obtained the yield from thunderstorm 14C generation evaluated as 1e-4% relative to cosmogenic one. The results support the hypothesis that radiocarbon rise in the old tree rings (at AD 774–775) 1 can be explained by increased Sun activity of the Sun at this time interval.

1. F. Miyake, K. Nagaya, K. Masuda, T. Nakamura, Nature 486, (2012) 240. doi.org/10.1038/nature11123
2. Joseph R. Dwyer · David M. Smith · Steven A. Cummer. High-Energy Atmospheric Physics: Terrestrial Gamma-Ray Flashes and Related Phenomena. Space Sci Rev (2012) 173:133–196. DOI 10.1007/s11214-012-9894-0.
3. Leonid Babich, Thunderous nuclear reactions. Nature, v.551 (2017) 443. doi.org/10.1038/d41586-017-07266-w
4. V. I. Lyashuk, Evaluation of Radiocarbon 14C Yield Under Conditions of Thunderstorms, Geophysical Research Letters, 48, e2021GL095357. https://doi.org/10.1029/2021GL095357
5. V.I. Lyashuk, ArXiv 2011.07417.

Speaker: Vladimir Lyashuk (Institute for Nuclear Research (INR) of the Russian Academy of Sciences)

V. Lyashuk_THUNDERSTORM FLASHES AS THE MECHANISM OF 14C GENERATION.docx

16:10 TIME-DEPENDENT DESCRIPTION OF THE REACTION $^{28}$Si($^{11}$Be,$^{10}$Be) AT LOW ENERGIES

The evolution of the probability density of the outer weakly bound neutron of the $^{11}$Be nucleus (Fig. 1) in collision with the $^{28}$Si nucleus is described based on numerical solution of the time-dependent Schrödinger equation [1, 2]. The probabilities of outer neutron removal due to the processes of neutron transfer and nuclear breakup are determined. The results of calculating the cross sections for removal of the outer neutron from the $^{11}$Be nucleus are close to the experimental data [3]. Numerical solution of the time-dependent Schrödinger equation taking into account spin-orbit interaction [4−6] makes it possible to study the dynamics of removal of the outer weakly bound neutron of the $^{11}$Be nucleus and to determine the contributions of the neutron transfer channels and nuclear breakup in low-energy collisions with a target nucleus.

Fig. 1. Evolution of the probability density for the outer neutron of the $^{11}$Be nucleus in the collision $^{11}$Be + $^{28}$Si at beam energy 55 MeV in the reference frame moving relative to the laboratory frame with a constant velocity equal to the velocity of the projectile nucleus at a sufficiently large distance from the target nucleus. The course of time corresponds to the direction from left to right.

1. A.K. Azhibekov, V.V. Samarin, and K.A. Kuterbekov, Chin. J. Phys. 65, 292 (2020).
2. A.K. Azhibekov et al., Phys. Atom. Nucl. 84, 635 (2021).
3. F. Negoita et al., Phys. Rev. C 59, 2082 (1999).
4. V.V. Samarin, Phys. Atom. Nucl. 78, 128 (2015).
5. Yu.E. Penionzhkevich, Yu.G. Sobolev, V.V. Samarin et al., Phys. Rev. C 99, 014609 (2019).
6. V.V. Samarin, Bull. Russ. Acad. Sci.: Phys. 84, 990 (2020).

Speaker: Aidos Azhibekov (JINR, Dubna)

nucleus-2022-abstract-Azhibekov1.docx

15:00 → 16:40 Intermediate and high energies, heavy ion collisions

Convener: Yuri Kharlov (Institute for High Energy Physics of NRC Kurchatov Institute (RU))

15:00 First measurement of the forward rapidity gap distribution in proton-lead collisions at LHC energy $\sqrt{s_{\mathrm{NN}}} = 8.16\mathrm{~TeV}$ with the CMS experiment

For the first time at LHC energies, we present the forward rapidity gap spectra from proton-lead (pPb) collisions for both pomeron-lead and pomeron-proton topologies. The analysis is performed over 10.4 units of pseudorapidity. The center-of-mass energy is 8.16 TeV per nucleon-nucleon pair, i.e., almost 300 times higher than previous measurements of diffractive production in proton-nucleus collisions. For the pomeron-lead topology, the EPOS - LHC predictions are a factor of two below the unfolded data, but the model does give a reasonable description of the spectrum's shape. For the pomeron-proton topology, the EPOS-LHC, QGSJET II, and HIJING generator predictions are all at least a factor of five below the data. This effect can be explained by a significant contribution of ultra-peripheral photoproduction events mimicking the signature of diffractive processes. The obtained data may be of significant help in understanding the high energy limit of QCD and modeling cosmic ray air showers.

Speaker: Dmitry Sosnov (NRC KI — PNPI)

nucleus-2022-abstract-dsosnov.docx

nucleus22_sosnov.pdf

15:20 Searches for new physics in the dilepton channel with the CMS detector at the LHC

Search for physics beyond the standard model using resonant and nonresonant models in dilepton channel has been performed using Run 2 data with integrated luminosity 140 fb-1 in proton-proton collisions at √s=13 TeV with the CMS experiment at the LHC.
A good agreement with the predictions of the standard model is found, no significant deviations are observed.
Limits on the parameters of the considered models are reported.

Speaker: Ilia Zhizhin (JINR)

Zhizhin_nucleus-2022-abstract.docx

15:40 Searches for Long-Lived Particles in CMS experiment

Many models beyond the standard model predict new particles with long lifetimes, such that the position of their decay is measurably displaced from their production vertex. We present recent results of searches for long-lived particles obtained using data recorded by the CMS experiment at the LHC

Speaker: Vladislav Shalaev (JINR, Dubna State University)

nucleus-2022-Shalaev.docx

16:00 Model study of the energy dependence of the correlation between anisotropic flow and the mean transverse momentum in Au+Au collisions

One of the key goals of the heavy-ion programs is to study the transport properties of the quark-gluon plasma (QGP) forming in the collisions of two nuclei, such as the specific shear viscosity η/s as a function of temperature T and baryon chemical potential μ_B. The precise extraction of such parameters may present a certain difficulties. To strengthen the constraints for η/s(T, μ_B) the modified Pearson correlation coefficient ρ(v₂²,[p_T]) between the average transverse momentum [p_T] and square of the elliptic flow coefficient v₂² might be employed.
In this work, sensitivity of the correlation coefficient ρ(v₂²,[p_T]) to the attenuation effects of the specific shear viscosity and the initial-state geometry of the collisions is studied using the UrQMD+vHLLE hybrid model to simulate Au+Au collisions. Measurements of the correlation between v₂² and [p_T] could aid precision extraction of η/s(T, μ_B) from the experimental data available at RHIC.

Speaker: Petr Parfenov (NRNU MEPhI)

nucleus-2022-abstract.docx

NUCLEUS2022_Parfenov.pdf

16:20 Geant4 FTF Model Description of the NA61/SHINE Collaboration Data on Strange Particle Production in pp-interactions

Geant4 FTF Model Description of the NA61/SHINE Collaboration Data on Strange Particle Production in pp-interactions

      A. Galoyan and V. Uzhinsky

Joint Institute for Nuclear Research, Dubna, Russia
E-mail: uzhinsky@jinr.ru

Geant4 is the well-known package for simulation of particle penetration in matter which is used in many high energy experiments. There is FTF (Fritiof) model in Geant4. The FTF model is responsible for simulations of elementary interactions. We compare the FTF model results on inclusive distributions of Λ, K0s, Ξ-, anti-Ξ+ and K(892)0 produced in pp interactions at Plab=158 GeV/c recently measured by the NA61/SHINE collaboration. It is found that for a good description of the K(892)0 mesons it is needed to set up the ratio of pseudo-scalar to vector meson probability as 0.4/0.6 in a production. A description of the Ξ- and anti-Ξ+ hyperons requires a special treatment of fragmentation of anti-diquark – diquark strings with low masses, and an additional tuning of quark and diquark fragmentation functions. With all of these, we reproduce Λ and K0s spectra well. It is the best model description of the strange particle production in the literature. The collaboration could not be able to describe its data using the EPOS 1.99 model.

Speaker: Vladimir Uzhinskii (Joint Institute for Nuclear Research (JINR))

Uzhinsky_12_07_2022.pdf

Uzhinsky.docx

15:00 → 16:40 Nuclear structure: theory and experiment

Convener: Alexander Mazur (Pacific National University)

15:00 Analysis of M1 excitations in $^{28}$Si using inelastic proton scattering

Isovector and isoscalar spin-flip excitations in even-even sd-shell nuclei excited by inelastic proton scattering were considered in [1]. Recently M1 excitations in sd-shell were also analyzed in [2]. In [2] only strongest excitations of $^{28}$Si were discussed. Shell model predicts for $^{28}$Si a few of 1$^+$ states with excitation energy lower than 20 MeV. Nearly all of these states can be identified with experimentally observed levels excited in (p,p’) and (e,e’) reactions. Here we analyze the spectrum of 1$^+$ states in $^{28}$Si excited in (p,p’) reaction in comparison with theoretical spectroscopic predictions. The calculations were carried out in the sd model space with the USDA Hamiltonian [3] using the code NuShellX [4].
The M1 excitations in light nuclei are mainly determined by the spin transition density. Current transition density play only minor importance in the observed B(M1) value. The B(M1) value can be extracted from the (e,e’) scattering experiments. On the other hand only spin transition density determine the forward cross section of (p,p’) reaction with the excitation of M1 states. We analyze forward cross sections of (p,p’) reaction with excitation of 1$^+$ levels in $^{28}$Si and determine the possible impact of current density in the B(M1) value.
In the excitation of M1 states with protons both T=1 and T=0 states are excited and only T=1 states can be excited in (e,e’). The theoretically predicted states can be identified with the observed 1$^+$ levels according to their excitation energy but the strength of the excitations can considerably differ from the theoretical prediction. The possible explanation of this difference may be the isospin mixture.

1. G.M. Crawley, C. Djalali, N. Marty et al, Phys. Rev. C 39, 311 (1989).
2. H. Matsubara, A. Tamii, H. Nakada et al, Phys. Rev. Let. 115, 102501 (2015).
3. B. A. Brown and W.A. Richter, Phys. Rev. C 74, 034315 (2006).
4. B. A. Brown and W. D. M. Rae, The Shell-Model Code NuShellX. Nuclear Data Sheets 120, 115 (2014).

Speaker: Mikhail Onegin (NRC "Kurchatov institute" - PNPI)

onegin2022.docx

15:20 STUDY OF 209Bi(γ,xn) REACTIONS IN ENERGY REGION UP TO 100 MeV

In order to follow relative yields of 209Bi(γ,xn) reactions, samples of natural bismuth were exposed in LINAC 200 bremsstrahlung beam at several different energies (40 MeV, 60 MeV, 80 MeV and 100 MeV). Activities of eight obtained products of photonuclear reactions with different neutron multiplicity, from (γ,2n) to (γ,9n) were detected. Relative yields were calculated for all of them. All measurements were normalized on 206Bi yield.

Obtained yields were compared with the results already available in literature. The data in the literature are not very abundant and in some cases the yields differ by a two orders of magnitude. In all measurements, including this one, it was confirmed that the reaction yield decreases very sharply with the number of neutrons emitted. It has also been observed that for a given multiplicity of neutrons, the relative yield does not depend significantly on maximal energy of the bremsstrahlung.

Yields obtained by measurements are compared with the results of theoretical calculations. Calculation have been performed using the combination of evaporation and exciton models [1]. The level densities employed in the model have been calculated microscopically to take into account shell effects and their dependence on excitation energy [2].

[1] B. S. Ishkhanov and V. N. Orlin, Physics of Atomic Nuclei 71, No. 3, pp. 493–508 (2008).
[2] A.Rahmatinejad, A.N.Bezbakh, T.M.Shneidman, G.Adamian, N.V.Antonenko, P.Jachimowicz, M.Kowal, Phys.Rev. C 103, 034309 (2021).

Speaker: Mikhail Demichev (JINR)

photonuclear_Bi.docx

15:40 First tests on GRAND set-up

GRAND is a Gas-filled Recoil Analyzer and Nuclei Detector (see Fig.1), which created for experiments on the synthesis of super heavy elements. Facility is installed at 4th beam line of the cyclotron DC-280[2] in the SHE Factory at FLNR [1]. This separator has the scheme QvDhQhQvD. Helium with a pressure of P=0.7-1.5 mBa is used as the gas. The ion optical calculations for the complete system have been checked by placing 226Ra source at the target position and transporting the emitted α-particles to a position sensitive detector at the focal plane.

As well as tests with complete fusion reactions 174Yb(48Ca,xn)222Th, 170Er(48Ca,xn)218Ra and 208Pb(48Ca,xn)256No* were done.

1. S. Dmitriev, et al., Status EPJ Web Conf.131 (08001) (2016) 1-6.
2. G.G. Gulbekian, et al., Phys. Part. Nuclei Lett. 16 (6) (2019) 866-875.

Speaker: Alena Kuznetsova (JINR)

Fig1.png

nucleus-2022-KuznetsovaAA-1.docx

16:20 DIRECT ONE-NEUTRON DECAY OF THE ISOSCALAR GIANT DIPOLE RESONANCE IN MEDIUM-HEAVY SPHERICAL NUCLEI: A SEMI-MICROSCOPIC DESCRIPTION

Direct one-nucleon decay of giant resonances (GRs) is the subject of permanent (but not-too-intensive) experimental and theoretical studies. They allow one to get information on GR structure and decay mechanisms. Decay probabilities are usually deduced from a common analysis of cross sections of direct inclusive and “decay” reactions. In Ref. [1], direct one-neutron decay of Isoscalar Giant Dipole Resonance (ISGDR) in 90Zr, 116Sn, and 208Pb have been studied via the (α,α^' )- and (α,α^' n)-reactions. To some extent, this study has been stimulated by predictions made in Ref. [2] for partial branching ratios b_μ of direct one-neutron ISGDR decay accompanied by population of neutron-hole states μ^(-1) in product nuclei. A simple extension of standard and nonstandard continuum-RPA versions to taking phenomenologically the spreading effect into account has been exploited in Ref. [2]. The experimental values b=∑_μ▒b_μ (the sum is taken over a few valence neutron-hole states) were found in Ref. [1] to be essentially less than the respective predicted values.
In the present work, we, first, specify the approach of Ref. [2], employing for evaluation of b_μ values the semi-microscopic Particle-Hole Dispersive Optical Model (see, e.g., Ref. [3] and references therein) and, secondly, use the alternative definition for b_μ employed in Ref. [1]. These points allow us to reduce markedly the difference between theoretical and experimental b values related to direct one-neutron decay of ISGMR in the above-mentioned nuclei.
This work is partially supported by the Russian Foundation for Basic Research, under Grant no. 19-02-00660 (M.L.G., B.A.T., M.H.U.), by the US Department of Energy, under Grant no. DE-FG03-93ER40773 (S.S.), and by the Program “Priority – 2030” for National Research Nuclear University “MEPhI” (M.H.U.).

1. Hunyadi M., Van den Berg A.M., Davids B., Harakeh M.N. et al., Phys. Rev. C 75, 014606 (2007).
2. Gorelik M.L., Safonov I.V., and Urin M.H., Phys. Rev. C 69, 054322 (2004).
3. Gorelik M.L., Shlomo S., Tulupov B.A., and Urin M.H., Phys. Rev. C 103, 034302 (2021).

Speaker: Mr Mikhail Gorelik (Moscow Economic School)

GSTU-nucleus-2022-abstract.docx

GSTU-Nucleus-2022-abstract.pdf

15:00 → 16:40 Nuclear technology and methods in medicine, radioecology.

15:00 DEVELOPMENT OF FAST NEUTRON THERAPY TPS

NIITFA is participating in development of new fast neutron machine for external beam therapy. It’s based on C-arm gantry and D-T neutron generator. So overall design is very close to conventional x-ray LINACs and rises similar problems of dose calculation. Due to unavailability of commercial treatment planning systems (TPS) for fast neutron dose calculation, development of new TPS has been started recently. The TPS architecture is based on brachytherapy PlanB (RT7 LLC) system [1]. Planning tab graphical user interface can be seen on Figure 1.

Fig. 1. Dose planning tab in developing TPS.

Dose calculation engine will be based on pencil beam (first step) and Monte-Carlo simulation (second step). Pencil beam algorithm is currently under implementation in system. Monte-Carlo calculations will use external general-purpose radiation transport code with dose calculation broker/pipeline, controlled by TPS server.
Developing TPS also can include numerous modern approaches for dose calculation, radiobiology models, dose optimization, etc. as it Russian-based and open for collaboration. But the main goal is clinic-ready TPS for external beam fast neutron therapy and we believe it will be available in close future.

1. Моисеев А.Н. Использование изображений разной модальности для реконструкции позиции аппликатора при брахитерапии. Трудный пациент. 2022; 20 (1): 54–57. doi: 10.224412/2074-1005-2022-8-54-57.

Speaker: Dr A. N. Moiseev

nucleus-2022-abstract-Moiseev.docx

15:20 DEVELOPMENT OF SIMPLE TREATMENT PLANNING SYSTEM BASED ON TOPAS MC GEANT4 CODE FOR FAST NEUTRON IRRADIATION

At present, NIITFA is developing a new medical device for fast-neutron radiotherapy based on the 14.1 MeV neutron source NG-24[1].
The neutron source NG-24 was simulated in the Topas MC Geant4 environment. The simulation result was compared with the previously obtained result from the MCNP code[2].
A Python console program for running multiple Topas simulations has been developed. The developed program supports the following functions: setting several irradiation fields (SDS, gantry rotation angle), loading the patient's CT and HU-ED curve for Geant4 simulation, viewing the received dose distributions in transverse coronar and siggital projections

Keywords: neutron generator, fast-neutron radiotherapy, Monte Carlo method, Python3

1. В.М. Литяев, В.В. Фёдоров, А.Н.Соловьёв, С.Е. Ульяненко Устройство для формирования терапевтических нейтронных полей на базе генератора НГ–24. Медицинская физика 2016 №2 94-100, Москва 2016
   2.Морозов В.Н., Моисеев А.Н., Холомов И.А., Зверев В.И. Исследование дозиметрических характеристик генератора нейтронов НГ-24 для терапевтического использования, Троицк, Россия 2020

Speaker: Maksim Trushin (NRNU MEPhI)

nucleus-2022-abstract_TrushinMS.docx

15:40 THE DOSIMETRY OF FLASH PROTON BEAMS

Proton flash therapy with high dose rates is at the forefront of cancer treatment. The phenomenon of flash effect is to reduce the damage to normal cells with an extreme dose rate increase of over 40 Gy/s.
Radiobiological experiments aimed at studying this phenomenon may require a special dosimetry equipment [1].
Our work consisted of the formation system settings [2] including the spread-out Bragg peak (SOBP) localization and measuring the absolute values of the absorbed dose in the SOBP region in the water phantom PTW MP3 P T41029.
We used PTW Advanced Markus Chamber Type 34045 ionization chambers (IC) in pair with Scanditronix IC-10 connected to a PTW MULTIDOSE electrometer for relative dosimetry.
For absolute dosimetry, we used a PTW 31010 IC and GafChromic EBT-XD films. The measured SOBP and the detectors’ location is shown in Figure 1. The result corresponds to a decrease of IC dose referred to film values by 15% in the conventional dose rate. At a dose rate above 50 Gy/s, the response of the films is an order of magnitude greater than the corresponding radiochromic film data. It indicates the impropriety of using ionization chambers in radiobiological experiments with proton beams at high and ultrahigh dose rates.

1. Desrosiers, Marc et al. “The Importance of Dosimetry Standardization in Radiobiology.” J Res Natl Inst Stan vol. 118 403-18. 30 Dec. 2013, doi:10.6028/jres.118.021
2. Akulinichev S.V., et al. Possibilities of Proton FLASH Therapy on the Accelerator at the Russian Academy of Sciences’ Institute for Nuclear Research. Bull. Russ. Acad. Sci. Phys. 84, 1325–1329 (2020).

Speaker: Ivan Yakovlev (INR RAS)

yakovlev nucleus-22.docx

16:00 SIMULATION THE EFFECT OF 11B ISOTOPE ON THE PROTON AND ALPHA PARTICLE DOSE DISTRIBUTIONS USING MONTE CARLO METHOD

The advantages of proton therapy make it useful for treating tumors located in the regions that surround radiosensitive tissues and, in the tissues, where surgical access is limited [1]. Recent studies [2-3] have indicated that Proton-Boron Capture Therapy (PBCT) induces tumor cell death through three alpha particles via the reaction between proton and 11B. When a proton reacts with boron (11B) based on the following equation, the 11B changes to 12C in an excited state. Then, the excited carbon nucleus splits into an alpha particle with the energy of 3.76 MeV and 8Be. Finally, 8Be splits into two alpha particles each with the energy of 2.74 MeV.
11B + p → 12C → 8Be + α →3α + 8.7 MeV (1)
The therapy results can be more effective than proton therapy if the energy deposition due to the alpha particles and the proton’s Bragg-peak in the tumor regions could be matched. Of course, further studies are needed to evaluate the use of PBCT in clinical practices. It is also important to investigate secondary particles in radiotherapy. Secondary particles such as neutrons and photons can be produced by the Coulomb interaction of protons with atomic electrons, elastic nuclear scattering, and the passing of protons through tissues. The main aim of this study was to determine the dose of protons and alpha particles for boron different concentrations, investigate the role of secondary particles in the PBCT treatment method as compared to the conventional proton beam therapy using Monte-Carlo simulation package FLUKA. To do so, first, the variation of the Bragg-peak dose and the depth of protons were examined depending on the boron concentration and the proton energy. The doses of these particles were calculated for boron concentrations in the range of 1; 1,5; …; and 5% and different proton energies including, 60; 90; 120; and 150 MeV.

Speaker: Mr Azizbek Abduvaliev (Institute of Nuclear Physics UzAs)

nucleus-2022-abstract.docx

16:20 Simulation of the proton beam facility at INR RAS using the TOPAS program

Proton therapy is currently attracting additional interest from specialists due to the possibility of using some proton accelerators in the FLASH mode with a dose rate of more than 40 Gy/s. The FLASH effect opens up new advantages for radiation therapy due to the predominant destruction of tumors. The proton beam facility at the INR of RAS makes it possible to achieve a record mean dose rate for proton accelerators, up to 106 Gy/s [1]. The calculation of the characteristics of a proton beam facility in extreme conditions is a necessary step in the experiments carried out on it. As is known, the Monte Carlo method is one of the most accurate and widespread methods for calculating the interactions of radiation with matter. Previously, we compared some options for using this method [2]. In this work, the beam-forming system of the INR beam facility is modeled using the TOPAS software package. Among the features of this program, one can single out the possibility of calculating the linear energy transfer (LET), which in proton therapy affects the relative biological effectiveness (RBE) of irradiation. Examples of calculation of LET for a real modified Bragg peak and effective dose for various models [3] of the dependence of RBE on LET are presented and compared with the absorbed dose D(z).
1. Akulinichev, S.V., et al. Possibilities of Proton FLASH Therapy on the Accelerator at the Russian Academy of Sciences’ Institute for Nuclear Research. Bull. Russ. Acad. Sci. Phys. 84, 1325–1329 (2020).
2. Grigorii V. Merzlikin , Sergey V. Akulinichev, Ivan A. Yakovlev, Comparison of the results of calculations using GEANT4 and SRNA, https://doi.org/10.21175/rad.abstr.book.2021.36.5
3. Paganetti et al.: TG-256 on the RBE of proton beams. Med. Phys. 46 (3), March 2019 0094-2405/2019/46(3)/e53/26.

Speaker: Grigorii Merzlikin (MSU, INR RAS)

Merzlikin nucleus22 final.doc

16:40 → 17:10 Coffee-break

17:10 → 19:00 Applications of nuclear methods in science and technology

Convener: Nikolay Novikov (Skobeltsyn Institute of Nuclear Physics Moscow State University, Moscow, Russia)

17:10 HIGH ENERGY IONOLUMINESCENCE DECAY IN Al2O3

Time-resolved ion beam induced luminescence (ionoluminescence, IL) measurements, especially those when the luminescence decay is registered after single ion impact may be efficiently used for real-time characterization of irradiating materials. Temporal resolution of single ion technique, not limited by beam pulse duration has enabled to reveal new interesting features in dynamics of dense electronic excitations in vicinity of swift ion trajectory [1,2]. The start pulses in such experiments are produced using electron emission from carbon foils generated by incoming ion. In this report we present the design of the IL detection system at IC-100 FLNR JINR cyclotron in which the start pulses are formed using electron emission immediately from the target surface. Such approach allows to narrow the instrumental response function and minimize inaccuracy in lifetime measurements arising due to dispersion in ion velocities. The experimental set-up has been used for studies of time-resolved ionoluminescence of intact and pre-damaged Al2O3 single crystals during single 1.2 MeV/amu Ne, Ar, Kr and Xe ion impact.
1. Kazuie Kimura, Wan Hong, Junichi Kaneko, Noriaki Itoh, Nucl Instr Meth B 141 (1998) 425-430.
2. Kazuie Kimura, Sumit Sharma, Anatoli Popov, Nucl Instr Meth B 191 (2002) 48–53.

Speaker: Askar Issatov (Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions)

nucleus-2022-abstract-template_Issatov.docx

17:30 INFINITE ELECTRON OSCILLATIONS NEAR THE CELL SEPARATOR IN THE SIMPLEST REACTOR

Today, there are many unsolved mysteries in the physics of atmospheric lightning discharge. The unexplained phenomenon of atmospheric electricity is gamma-ray bursts observed since 1994 by space gamma-ray observatories (for example, BATSE, Fermi), created for observing gamma radiation from astrophysical sources. Mysterious natural gamma radiation of the earth's atmosphere is called Terrestrial Gamma-ray Flushes (TGFs). Long-term observation of TGF made it possible to establish that, apparently, this natural phenomenon is based on the acceleration of relativistic electrons in the electric fields of thunderclouds. Actually, the fundamental phenomenon is the avalanche-like multiplication of fast electrons in matter. This phenomenon was proposed by Gurevich [1], it is called runaway breakdown.
If we investigate the propagation of relativistic avalanches of runaway electrons at a sufficiently large value of the electric field in the case of two adjoining parts of the cloud with opposite directions of the electric field. In the simulation, this configuration can be described as a system of two cells with different field directions and called the simplest reactor. Under certain conditions of the system, the initiation of feedback is possible. Electrons due to the presence of a field in the system will be accelerated, and when they get into the field in the opposite direction, they will turn. Along the way, they will emit gamma quanta, on which the field does not act, thus playing a key role in the formation of a non-stop process.
In this paper, electrons were described that exist in the system and, under the action of a field, can begin to oscillate near the plane of separation of two cells, thereby maintaining feedback in the system of a simple reactor. This relationship can exist even at small cell sizes and small margins. This means that for the explosion criterion in a reactor, not only the gamma feedback is essential, but also electronic communication, contributes to the development of gamma communication.
The purpose of this work was to study the process of gamma and electron multiplication for the simplest reactor, by modeling on GEANT4. The studies were carried out for particles with an energy of 5 MeV at a height of 10 km from the Earth's surface.

Speaker: Daria Zemlianskaya

247-nucleus-2022-abstract.doc

nucleus-2022-abstract-template.docx-2.pdf

17:50 Relativistic runaway electron avalanche acceleration in complex thunderstorm electric structures

Thunderstorms in the Earth’s atmosphere produce short and intense gamma-ray bursts [1]. Such bursts are called Terrestrial Gamma-ray Flashes (TGF). One of possible mechanisms of thunderstorm gamma-radiation – acceleration of Relativistic Runaway Electron Avalanches (RREA) in thunderstorm electric fields [2]. Gamma-rays are produced by relativistic electrons bremsstrahlung.
RREAs are formed by secondary cosmic rays within thunderstorm media. In strong electric fields RREAs are further multiplied by positive feedback mechanisms, which can lead to self-sustainable high-energy particles generation in thunderstorms (infinite feedback) [2,3]. In complex thunderstorm electric structures RREAs are multiplied efficiently due to high-energy particles exchange (reactor feedback) between different electric regions (cells) [3].
In this research, reactor feedback by runaway electron transport between cells is studied. It is shown that runaway electron propagation between cells with its further acceleration and multiplication plays an important role in the RREA dynamics. The conditions necessary for TGF by this mechanism are derived.

Speaker: Egor Stadnichuk (MIPT, HSE University)

nucleus-2022-abstract-Stadnichuk.docx

Stadnichuk Nucleus 2022.pdf

18:30 Compton scattering of entangled and decoherent annihilation photons

At present, positron emission tomography (PET) is one of the most effective instruments for the medical diagnostics. This method is based on detection of two 511 keV gammas produced in positron-electron annihilation in organic tissue. According to the theory, these annihilation photons are in entangled quantum state and have mutually perpendicular linear polarizations. This feature is suggested to be used in future generation of PET-scanners, where the angular correlations of scattered annihilation photons can be applied for suppression of backgrounds and improvement of image quality. It is supposed that the angular correlations are quite different for the scattered annihilation photons in entangled and decoherent quantum states that allows the rejection of decoherent photons and hence to improve the signal/noise factor. Nevertheless, the experimental comparison of Compton scattering of entangled and decoherent annihilation photons was not done till now. We constructed the setup that allows the identification of the quantum state and the study of angular correlations of scattered annihilation photons. First experimental results on Compton scattering of entangled and decoherent annihilation photons are presented.

Speaker: Sultan Musin (INR RAS(Moscow), MIPT(Moscow))

nucleus-2022-abstract-template (1).docx

17:10 → 19:00 Experimental and theoretical studies of nuclear reactions: NR1 Experiment neutrons

Convener: Yuri Kopatch (Joint Institute for Nuclear Research (JINR), Dubna, Russia)

17:10 ASYMMETRY EFFECTS MODELLING IN SLOW NEUTRONS INDUCED PROCESSES ON 35CL NUCLEUS

Asymmetry and spatial parity non-conserving effects were investigated in slow neutrons induced processes on 35Cl nucleus. Forward — backward, left — right and parity non conservation effects were evaluated in the (n,p) reaction for neutrons energy up to 1 keV. Cross sections, necessary angular correlations, asymmetry and spatial parity breaking effects were evaluated in the frame mixing parity of compound nucleus states with the same spin and opposite parities [1,2]. Theoretical evaluations of the effects were compared with experimental data obtained at FLNP JINR Dubna and Peterburg Nuclear Physics Institute [3,4]. Forward — backward, left — right and parity non conservation effects are important because using theoretical evaluations and experimental results, matrix element of weak non leptonic interaction can be obtained [4].
For each investigated effect, angular correlations were obtained using (n,p) reaction amplitudes from [1,2]. Further, applying direct Monte-Carlo method theoretical expressions and numerical evaluation of protons angular distributions were obtained considering different possible terms in angular correlations. Using protons angular distribution, computer simulation of the asymmetry and parity breaking effects were realized considering targets with finite dimensions and different densities. For each analyzed effect. precision of the experiment was determined and from computer modeled asymmetry coeffcients weak matrix elements was extracted.
The present results will be applied in the investigations of new experiments proposed at intense neutrons source IREN, from FLNP JINR Dubna dedicated for the measurements of asymmetry effects in the 35Cl(n,p)35S nuclear reaction with slow neutrons.

1. V.E. Bunakov, L.B. Pikelner, Progess in Particle and Nuclear Physics, 39, 337 (1997).
2. V.V. Flambaum, G.F. Gribakin, Progess in Particle and Nuclear Physics, 35, 423 (1995).
3. A. Antonov, V.A. Vesna, Y.M. Gledenov, Soviet Journal of Nuclear Physics, 48(2), 193 (1988).
4. A.I. Oprea, C. Oprea, Yu.M. Gledenov, P.V. Sedyshev, C. Pirvutoiu, D. Vladoiu, Romanian Reports in Physics, 63(2), 357 (2011)

Speaker: Alexandru Ioan Oprea (Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, MO, Russian Federation)

445-AIOpreaAbsNucleus2022-.docx

PrezSimMCAOprea.ppt

17:30 ESTIMATİON OF THE REACTION CROSS SECTION Li(n,α)T

The presented work is carried out analyzes and evaluation of available experimental data on the Li(n,α)T reaction cross section in order to obtain the recommended data. The reaction cross section Li(n,α)T--σnα (En) in neutron physics is often used as a reference quantity. In the neutron energy range En from 0.025 eV to 100 keV, the cross section is known with an accuracy of 1÷3%. In the energy range 500 KeV<En<1.7 MeV, the accuracy is about 15%. As for the energy interval from 100 keV to 500 keV, there are significant uncertainties due to the strong resonance around the neutron energy of 250 keV. In estimating [1] for this energy range, the values of the cross section were recommended, which were obtained from the condition of the best description of the total cross section, the neutron elastic scattering cross section, and the reaction cross section (n,α). Recently, new data on the Li(n, α)T reaction cross section have appeared. The behavior in the energy range 100 keV≤En≤500 keV was studied in particular detail. As noted at the meeting on neutron data, the results of work performed in the energy range 150 KeV≤En≤400 KeV are consistent with each other within ±4%, if we accept a systematic shift in energy (about 5 KeV) of the work results and renormalize the cross sections obtained in work [2] down by 5%.
In this paper, was compared the results of parametrization of experimental data for the energy range 2 KeV≤En≤1500 KeV by the least squares method using a number of different approximations. In this case, the results of different authors are accepted as equal and the errors they cite are not taken into account. As a first approximation, an expression was used that includes the resonant term in the dependence 1/ν (1):
(1)
Here, A, B and are constants, E0 is the resonance energy, Г is the resonance width, A, B, E and are fitting parameters. As a result of processing, the following values were obtained for them:
А=0,0141; В=0,1350; Е0=0,2410; Г=0,1050 и Δσ=0,0260
In this case, the value of χ2 at the point, averaged over the region of 2÷1500 keV, was 3.5 , and the root-mean-square deviation δ0, calculated as:

and averaged over the same energy range was 7.5%. The calculation results together with the experimental data are given in the works [2,3]. In the energy range 2 KeV≤En≤500 KeV, expression (1) describes the experimental data quite well. For En≤500 KeV, the description is much worse.

References:

1. Ignatyuk A.V., Ivanov A.I., Samsonov I.N. et al.// "Neutron physics", Obninsk, 2001 part I, p.325.
2. Balashov V.V., Nikolaev M.M.// "Nuclear constants", Obninsk, 1998, part 2, p.643.
3. Linnik Yu.V.// Theory of the optimal experiment M. "Nauka", 1998.

Speaker: Dr Bakhtiyar Najafov (Institute of Radiation Problems of Azerbaijan National Academy of Sciences )

Thyesis-B.A.Nadjafov (1) (8).docx

17:50 TalysLib: a ROOT-based toolkit for nuclear data access

Information about nuclear reactions and properties of nuclei is often needed during nuclear data processing. Access to the nuclear databases from applied software is often difficult because of complex file format or database structure. To simplify usage of the nuclear data a specific toolkit TalysLib was developed.
TalysLib is a ROOT-based C++ object-oriented library. It uses wide capabilities of ROOT [1] for data visualization and transformations. The main source of the evaluated data for TalysLib is the TALYS [2] program. Information about nuclear structure is extracted from RIPL-3 [3]. Work on the ENDF [4] data and preprocessed EXFOR data [5] support is in process.
TalysLib can be used for optimization of the theoretical model parameters using MINUIT package which is included in ROOT.
The structure of the TalysLib and its main features will be presented. Current version of the TalysLib is available on https://github.com/terawatt93/TalysLib.

1. R. Brun, F. Rademakers. Nucl. Inst. & Meth. in Phys. Res. A 389 (1997) 81-86.
2. A. J. Koning, S. Hilaire, M. C. Duijvestijn «TALYS-1.0», Proceedings of the International Conference on Nuclear Data for Science and Technology. EDP Sciences, 211(2007).
3. R. Capote, M. Herman, P. Oblozinsky et al. Nuclear Data Sheets. 110, 3107(2009).
4. D.A. Brown, M.B. Chadwick, R. Capote et al. Nucl. Data Sheets 148, 1(2018).
5. A. Koning. IAEA NDS Document Series IAEA(NDS)-235 (2020). https://www-nds.iaea.org/talys/tutorials/exfortables.pdf

Speaker: Nikita Fedorov (JINR)

nucleus-2022-abstract-template.docx

Presentation.pdf

18:10 Segmented HPGe Detector for Nuclear Reactions Research

This work presents the results of a study of the new true coaxial high-purity germanium p-type detector with a segmented n+ region. One of the main features of the detector is flowing endcap, which is allow to place a source or target inside of the detector. Thanks to it and six-fold segmentation of the crystal, it is possible to determine the direction of individual photons emitted from the source or during a nuclear reaction between ion beam and a target inside the ionizing radiation source. At the same time the flowing endcap give’s possibility to study not only γγ, but also αγγ- or βγγ- correlations, by the possibility to install the six-fold Si-detector inside of the HPGe detector.

Speaker: Артём Быстряков

тезисы ЯДРО Быстряков.DOCX

17:10 → 19:00 Experimental and theoretical studies of nuclear reactions: NR2

Convener: Alla Demyanova (NRC KURCHATOV INSTITUTE)

17:10 OPTICAL MODEL ANALYSIS OF PROTON ELASTIC SCATTERING ON 6Li NUCLEI WITH RESONANCE CONTRIBUTION

Optical model analysis [1] of proton elastic scattering on 6Li nuclei at proton energy from 50 keV to 185 MeV was continued with the use of the optical-model program code OptModel [2] taking into account the resonance contribution. Polarization data [3] in 1.21 to 3.22 MeV proton energy Ep range were added into set of the early used elastic scattering experimental data.
1. L.N. Generalov, V.A. Zherebtsov, S.M. Selyankina, Bull. Russ. Acad. Sci. Phys. 85. 1136 (2021).
2. L.N. Generalov, V.A. Zherebtsov, S.M. Taova, Bull. Russ. Acad. Sci. Phys. 80. 295 (2016).
3. C. Petitjean, L. Brown, R.C. Seyler, Nucl. Phys. A. 129. 209 (1969).

Speakers: Ms S. M. Selyankina (Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics) , Ms S. M. Selyankina (Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics)

abstract_optica_6Li_7_eng.doc

17:30 ELASTIC PROTON SCATTERING BY NUCLEI 7Ве AND 8В AT ENERGY 700 MeV

In this paper, based on Glauber's diffraction theory, we analyze the results of a recent experiment [1] on the scattering of protons by 7Ве and 8В nuclei at an energy of 0.7 GeV/nucleon, in the range of momentum transfer 0.002≤ |t|≤ 0.05 (ГэВ/с)2. The experiments were carried out by the GSI-PNPI collaboration (Germany-Russia) on the GSI radioactive beam (Darmstadt, Germany) in inverse kinematics.
In our calculations, the internal state of the 7Ве and 8В nuclei under study are described on the basis of (α-τ) two- and (α-τ-p) three-particle cluster models, respectively. The wave functions of these nuclei [2], obtained on the basis of the above cluster models, describe well their static characteristics.
The parameters of the elementary NN- and Nα-amplitudes required for our calculations are taken from other works. However, there are currently no data on elementary Nτ amplitudes in the scientific literature. In this connection, we separately considered elastic p3He scattering in the kinematic region in which it corresponds to our calculations for proton scattering by 7Be and 8B. We succeeded in describing satisfactorily the experimental data on p3He scattering [3]. Further, the calculation scheme used here was transferred to calculations on p7Be and p8B scattering.
Our calculations of proton scattering by 7Ве and 8В are in good agreement with the data of [1]. However, these experiments were performed for small scattering angles. We carried out calculations up to scattering angles of ~ 50° and determined the contributions to the cross section from one-, two-, and three-fold scattering. At small angles, single scattering dominates, the contribution of double scattering is compared with it in the region of 25°. The contribution of triple scattering in elastic p8B scattering appears at 40°. In the future, it is planned to carry out similar calculations on the scattering of π- and K-mesons and to carry out a comparative analysis of the obtained calculations.
This work is carried out within the framework of the scientific project АР08855589

1. A.V. Dobrovolsky et al. / Distribution of nuclear matter in proton-rich 7Be and 8B nuclei by elastic scattering of protons of intermediate energies in inverse kinematics/ Nuclear Physics A 989 (2019) 40–58
2. Dubovichenko S.B. (2011) Thermonuclear processes of the Universe. Almaty, Fesenkov V.G. Astrophysical Institute "NTsRT" NSA RK, 402. (in Russian).
3. Abdramanova G.B., Imambek O., Nadir A., Myrzabaeva M. / Elastic scattering of protons on 3He nuclei at intermediate energies / Proceedings of the Academy of Sciences of the Republic of Kazakhstan 1 (341) (2022) 117-123

Speaker: Onlassyn Imambek

17:50 PROTON INDUCES PROCESSES ON STRONTIUM ISOTOPES

In this study, proton capture and (p,xn) nuclear reactions on natural isotopes of Sr were investigated at incident protons up to 30-35 MeV. Taking into account all nuclear reaction mechanisms, cross sections, angular distributions, and isotope productions have been analyzed. A Hauser-Feshbach formalism was employed to describe compound processes, an approximation of Distorted Wave Born Approximation for direct mechanisms, and an exciton model to explain pre-equilibrium processes [1-3]. In this study, the contribution of the nuclear reactions mechanisms to the cross sections and angular distributions is discussed. These theoretical evaluations were compared with experimental data from literature and with those obtained from FLNP JINR Dubna facilities. Experimental data of fast proton-induced reactions are consistent with theoretical results. Based on the good agreement between theoretical and experimental results, it was possible to derive the dependence of the isomer ratios on the protons' energy. Several calculations use isotope ratios to evaluate spin distributions of reaction products, densities of nuclear states, and nuclear deformation in final states. Computer simulations were conducted to evaluate the production of Yttrium, Rubidium, and other isotopes using angular distributions of incident protons for different targets and intensities of incident protons. Calculations for isotopes and isomer production were compared with experimental data gathered from the literature.
For future experiments at JINR's Dubna facilities involving fast neutron induced reactions, the present data will be used.

1. W. Hauser, H. Feshbach, Phys. Rev, 87, 366 (1952).
2. N. Austern, Direct Nuclear Reaction Theories, New-York, Willey-Interscience (1970).
3. A.J. Koning, J.M. Akermans, Phys. Lett. B, 234, 417 (1990).

Speaker: Cristiana Oprea (Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, MO, Russian Federation)

COprea_Nucleus2022_Abstract.docx

Sr_nat_Oprea1.ppt

18:10 Analysis of cluster radioactivity using Q-value dependent relative separation

The spontaneous disintegration of an unstable nucleus to attain a relatively stable configuration is known as radioactivity. Generally, it is considered that the radioactive decay happens via emission of the alpha particle, beta particle and gamma radiation. Apart from this, cluster radioactivity (CR), heavy particle radioactivity (HPR) and spontaneous fission (SF) are also probable ground state emission modes. The spontaneous splitting of a unstable parent nucleus into fragment heavier than the α-particle but lighter than the fission fragments is known as cluster radioactivity (CR). It was theoretically predicted in [1], and then experimental verification was done by Rose and Jones [2], where 14C was detected from 223Ra radioactive parent nucleus. In past few decades, different experimental and theoretical attempts [3,4] were made to explore the cluster radioactive emission modes. Numerous theoretical models are introduced to explore such complex decay mode on the basis of different nuclear properties (size, shape, magicity etc.).The preformed cluster model (PCM) is one such model [5] which is successfully employed to address the cluster radioactivity and other competing ground state decay modes. PCM works out in terms of the mass asymmetry coordinate η and relative separation distance R. The preformation probability (η-motion) and the penetration probability (R-motion) are calculated at a fixed turning point Ra, which is the sum of the relative separation at touching configuration and the neck length parameter “∆R”. In the present work, we have estimated Q-value dependence of Ra ,which can be further utilize to calculate the decay half-lives and other decay properties of the radioactive nuclei. The work includes the study of CR by taking spherical choice of the decaying fragments. It will be of further interest to extend this work to study the comparative analysis of cluster dynamics with other ground state channels such as alpha-decay, hpr,and sf etc.

Speakers: Ms Chahat Jindal (Thapar Institute of Engineering and technology,Patiala,India) , Mr Nitin Sharma (School of Physics & Materials Science, Thapar Institute of Engineering and Technology, India, Patiala 147004, India) , Mr Manoj Kumar Sharma (School of Physics & Materials Science, Thapar Institute of Engineering and Technology, India, Patiala 147004, India)

177-nucleus-2022.docx

Chahat_Conf_177.pdf

nucleus-2022 abstract.pdf

17:10 → 19:00 Intermediate and high energies, heavy ion collisions

Convener: Yuri Kharlov (Institute for High Energy Physics of NRC Kurchatov Institute (RU))

17:10 Measurement of neutral pion production in Ag+Ag collisions at 1.23 AGeV beam energy at the HADES experiment

The High Acceptance DiElectron Spectrometer (HADES) is a fixed target experiment which explores the properties of hadronic matter in collisions of pions, protons and ions with various nuclei at beam energies 1-2 A GeV. It operates at the SIS18 accelerator in GSI, Darmstadt. Due to the newly built electromagnetic calorimeter ECal the HADES has a possibility to measure yield of the neutral pions via π0 → γγ decay. These measurements play an important role in reducing the systematic uncertainties in study of dilepton spectra.
The analized data were collected in Ag + Ag collisions at the beam energy 1.23 A GeV. The events with centrality 0-30 % were chosen for the analysis. The procedure of measurement of π0 yield and its uncertainty are discussed in this talk. The calibration of the ECal detector, acceptance and efficiency corrections and extrapolation of the pt and y spectra will be discussed.

Speaker: Arseniy Shabanov

281-NUCLEUS_Shabanov.docx

Shabanov_NUCLEUS2022.pdf

17:30 Study of charged spectators multiplicity distributions in nucleus-nucleus reactions at the HADES experiments

Multiplicity distributions of charged spectators with Z=1, 2, 3 measured
at the HADES experiments in reactions Ag+Ag at 1.58 AGeV and Au+Au at
1.23 AGeV will be presented. The experimental data have been obtained by
Forward multichannel scintillation detector, Forward Wall (FWall). The
multiplicity distributions of charged fragments for different centrality
classes have been compared with simulated ones obtained in the SHIELD
and DCM-QGSM-SMM models.

Speaker: Irina Yumatova (INR RAS & NRNU MEPhI)

Nucleus2022_presentation.pdf

17:50 Test of full PSD readout chain at the mCBM

The forward hadron calorimeter (PSD – Projectile Spectator Detector will be used at the Compressed Baryonic Matter (CBM) experiment at FAIR to measure the nucleus-nucleus collision centrality and orientation of the reaction plane. The PSD is a sampling lead/scintillator with modular transverse structure and longitudinal segmentation. The PSD has 46 modules with 10 longitudinal sections in each module. Light readout from each section is provided by Hamamatsu MPPC installed at the rare side of modules.
The PSD FEE and readout system is based on the ADC FPGA board, which was originally designed for ECAL at PANDA. This board employs two Kintex-7 FPGAs, which are processing the incoming data from ADCs with 14-bit resolution and 125MHz digitization rate for 32 channels per one FPGA. Due to high radiation doses and neutron fluences expected at the CBM, PSD readout electronics will be placed in the radiation protected room. Boards with photodetectors (MPPCs) will be placed on the back plane of the PSD without preamplifiers and will be connected with 60m coaxial cable with readout electronics placed outside of the cave.
The developed data acquisition system registers signals from 2.5 mV to 1.5 V, which provides coverage of the dynamic range x500 when adjusting the voltage corresponding to photodetectors for temperature correction of their gain. Direct digitization of low amplitude signals without the use of active electronics on the detector side is a new approach for the detector's readout system in nuclear physics, which makes it possible to realize the maximum possible dynamic range of the detector.
The full chain of the FEE and readout electronics of one PSD module - "mini PSD" (mPSD) has been assembled at mCBM. The readout has been integrated into mCBM trigger-less data acquisition system. Details of the PSD readout electronics, signal processing and transmission within the common synchronized mCBM data transport system will be shown.

Speaker: Dmitry Finogeev

Finogeev_CBM_PSD_readout_v1.pdf

nucleus-2022-psd_finogeev.docx

18:10 Upgrade of Projectile Spectator Detector at NA61/SHINE experiment

Projectile Spectator Detector (PSD) is a sampling hadron calorimeter used in the NA61/SHINE experiment to provide measurement of collision centrality and event plane reconstruction independently from tracking detectors. The PSD consists of modules with longitudinal segmentation based on lead/scintillator layers with the sampling ratio 4:1. Light from scintillator plates is collected with WLS fibers and each six consecutive scintillator plates are read out by one Hamamatsu MPPC placed at the end of the module. A fast analog signal from PSD modules allows to select events with required centrality on-line at the trigger level. Performance of the PSD will be shown for the measurements at the energy range 13 – 150 AGeV.
New physics program of NA61/SHINE experiments beyond 2020 includes open charm measurements. Current beam rate has to be increased by an order of magnitude. This requires PSD upgrade to survive in new high radiation conditions and to have faster photodetectors and read-out electronics. Instead of the present PSD, it is proposed to use two forward calorimeters. The first one is modified current PSD with constructed beam hole in the center and the second one is a new calorimeter with small transverse sizes placed downstream. Details of the PSD upgrade including simulation results of radiation conditions as well as results of the performance studies for new calorimeter system will be presented.

Speaker: Sergey Morozov (INR RAS)

250-NUCLEUS_2022_Abstract_Upgrade_PSD_NA61_SHINE.docx

Morozov_NUCLEUS_2022.pdf

18:30 MCDST: A UNIFIED STORAGE FORMAT FOR HEAVY ION COLLISION SIMULATED DATA

Each Monte Carlo generator used for heavy-ion collision simulations has a specific output form of simulated events. This fact complicates data storage and prevent standardization of processing data generated considering different models.
The McDst format is implemented to work around this. The format allows to store and smoothly read simulated data, that obtained from different generators, for analysis performance. To take advantage of the McDst unified approach a set of convertors for popular MC generators output formats is also implemented. Discussed programming solution is developed in C++ using ROOT libraries.
In this talk, the architecture of the McDst format is presented. A quick start guide to ease simulated data processing is also provided.

Speaker: Ekaterina Kuzina (NRNU MEPhI)

nucleus-2022-abstract-Kuzina.docx

NUCLEUS2022_Kuzina.pdf

17:10 → 19:00 Nuclear structure: theory and experiment

Convener: Alexander Mazur (Pacific National University)

17:10 THE HALF-LIFE OF 229mTh ISOMERS IN ACID SOLUTION

The 229mTh isomeric state with an energy of about 8 eV is formed in 2% of the cases of 233U α-decay (see ref. [1] and references therein). For neutral 229mTh atoms, the main decay channel is nonradiative – it is either electronic conversion or decay via an electronic bridge. An estimate of the probability of a decay with photon emission γTh gives a half-life T1/2 ≈ 2 h and is much smaller than the probability of a nonradiative transition. Photons can only be observed for 229mTh ions when the nonradiative channel is closed.
Here we give a detailed analysis of work [2], where γTh photons were observed for 4+ ions of 229mTh in HCl acid solution obtained in an ion exchange column from 0.1 g U (the relative α-activities of 233U and 232U were 99.8% and 0.02%, respectively). In each of several experiments four samples were sequentially prepared with 229mTh in 7M HCl aqueous solution by eluting once an hour fresh Th from U, which was previously purified from Th and its daughters. Sources for
α-spectrometry were prepared from the second and third samples; for each of them the α-activity of Th daughters increased with time. Thus, the α-activity of the samples could not lead to their damped photon emission.
The first and fourth liquid samples of 229mTh were placed into thin-layer quartz cuvettes, and t = 60 min after Th elution, the photon counting intensity N(t) from the samples was measured by a photomultiplier with a Sb-Na-K-CS photocathode, the photo efficiency was about 1% in the wavelength range of 300 – 800 nm. The time dependence of N(t) averaged over all experiments was approximated as , where A = 9  3, T1 = 22  3 min, T2 = 290  50 min (errors are one standard deviation). N0 was proportional to the -activity of 229Th in the samples with an accuracy of 20% and did not correlate with their total -activity. It can be assumed that for the 229mTh isomer in an HCl solution, T1/2 is in the range of 20 – 400 min. To refine T1/2 and the isomeric transition energy, it is necessary to study the photon spectrum of such samples.

1. B.S. Nickerson, M. Pimon, P.V. Bilous et al.// PRA. 103, 053120 (2021).
2. V.V. Koltsov, T.E. Kuzmina, D.N. Suglobov. Half-life measurement of the 229Th isomer. Proc. Int. Conf. on Nucl, Phys., Moscow, June 16–19, P. 266 (1999).

Speaker: Vladimir Koltsov (Khlopin Radium Institute, Saint-Petersburg, Russian Federation)

Abstracts Koltsov - Kuzmina - Nucleus 2022 .docx

Report Koltsov - Kuzmina - THE HALF-LIFE ... .ppt

17:30 NATURAL WIDTHS OF ATOMIC LEVELS IN THORIUM DETERMINED BY THE ICES METHOD

The overwhelming majority of the experimental atomic-level widths in thorium (see, e.g., the compilation [1]) were determined by the X-ray emission spectroscopy and only several N-subshell values were obtained by the XPS method. There are no available relevant experimental data determined by another methods. Therefore, we used suitable conversion electron lines of the 9.2, 15.1 and 24.3 keV nuclear transitions in 227Th (generated in the ꞵ ̶ decay of 227Ac) measured in the works [2,3] for the determination of the M1, M2, M3, N1, N2, and N3 atomic-level widths using the approach and the computer code [4]. The values obtained are given in the table (in eV).

Atomic subshell
M1  M2  M3  N1  N2  N3

This work 14.1±0.5 11.4±0.5 6.9±0.4 11.4±1.4 8.6±1.2 6.0±0.7
Ref. [1] 15.5±2.0 13.2±(5÷25)% 8±(5÷25)% 11.5±(10%) 8.8±0.8 7.5±1.0

As can be seen, the agreement within 2σ (or better) is found between the present and compilated data [1] and for the most of the atomic subshells in question our values are more precise. Thus, our data represent a valuable contribution to the database of the experimental natural atomic-level widths of thorium.

[1] J.L. Campbell, T. Papp, Atom. Data Nucl. Data Tables, 77 (2001) 1.
[2] A. Kovalík et al., Eur. Phys. J. A, 55 (2019) 131.
[3] A. Kovalík et al., Eur. Phys. J. A, 57 (2021) 285.
[4] A. Inoyatov et al., J. Elect. Spec. Relat. Phenom., 160 (2007) 54.

Speaker: Anvar Inoyatov (Joint Institute for Nuclear Research, Dubna)

Conference_contribution_2_2022_1.docx

17:50 EXPERIMENTAL INVESTIGATIONS OF THE 9.2, 15.1, AND 24.3 keV NUCLEAR TRANSITIONS IN 227Th AND CONSEQUENCES OF THEIR RESULTS FOR SPIN-PARITY ASSIGNMENTS TO LOW-LYING STATES OF 227Th

The 9.2, 15.1, and 24.3 keV nuclear transitions in 227Th were studied in the --decay of 227Ac by means of the internal conversion electron spectroscopy (ICES) using the combined electrostatic electron spectrometer [1] and the computer code SOFIE (see, e.g., Ref. [2]) to clarify the spin-parity assignment of the ground state and the two lowest excited states in 227Th. Results obtained were published in [3,4,5].
Energies of (9244.6±0.8), (15098.6±1.0), and (24343.1±1.1) eV were determined for the 9.2, 15.1, and 24.3 keV transitions, respectively, as well as the mixed character (M1+E2) for each of them with the δ2(E2/M1) values of (0.695±0.248), (0.0012±0.0003), and (0.0116±0.0004), respectively. An agreement within ±0.1 eV was found among the above transition energy values and those obtained from their interlinked relations based on the decay scheme. Using the gamma-ray spectroscopy, energy values of (24342.9±1.2), (28613.3±1.7), and (37860.2±2.0) eV were obtained for the 24.3, 28.6, and 37.8 keV transitions in 227Th, respectively. The almost zero difference of (0.2±1.6) eV for the 24.3 keV transition energies determined by the ICES and gamma-ray methods demonstrates a reliability of the transition energy determination in the present work.
Our investigation removed the uncertainty in the multipolarity character of the 15.1 keV transition. Determined [4] nonzero value of δ(E2/M1) parameter for the 9.2 keV transition questioned the current theoretical interpretation of low-lying levels of 227Th. Our calculations [4] prefer the 1/2+, 3/2+, and 3/2+ sequence instead of the adopted 1/2+, 5/2+ and 3/2+ one for the 0.0, 9.2, and 24.3 keV levels, respectively. In such a case, the assignment Iπ=5/2+ for any of these levels is excluded. Nevertheless, it is necessary to use more precise theoretical approaches to prove the proposed interpretation of the current experimental data. New experimental information on low-energy transitions connecting low-lying levels in similar nuclei is desirable as well.

1. Ch. Briançon et al., Nucl. Inst. Meth, 221 (1984) 547.
2. A. Inoyatov et al., J. Elect. Spec. Relat. Phenom., 160 (2007) 54.
3. A. Kovalík et al., Eur. Phys. J. A, 55 (2019) 131.
4. A. Kovalík et al., Phys. Lett. B, 820 (2021) 136593.
5. A. Kovalík et al., Eur. Phys. J. A, 57 (2021) 285.

Speaker: Dr Anvar Inoyatov (Joint Institute for Nuclear Research, Dubna, NPI ASUzR, Ulugbek, Uzbekistan)

Conference_contribution_2022_5.docx

18:10 OCTUPOLE EXCITATIONS IN 238U

Currently, one of the topical research areas in the field of the nuclear structure experimental and theoretical studies is the experimental and theoretical study of the negative parity states in the actinide nuclei [1]. In the 238U nucleus, rotational bands based on the ground and octupole vibrational states are known. Most of the experimental data were obtained using Coulomb excitation [2] and in reactions with heavy ions [3,4]. In the gamma transition probabilities from the octupole bands to the levels of the ground state band, noticeable deviations from the Alaga rules which are valid in the adiabatic approximation reveal.
The experimental data were analyzed within the framework of microscopic and phenomenological models [5,6]. Results of the microscopic model [5] disagree with the experiment. In [6], within the framework of the cluster model, a number of levels with odd spins belonging to the band were predicted, which was confirmed by experiment [1].
In this work, within the framework of the phenomenological model [7] considering the Coriolis mixing of octupole bands with , and the energies, state structures, and reduced E1 transition probabilities from negative parity states to the ground state band and to the states of β- and γ- bands with and are calculated. The theoretical results agree satisfactorily with the experimental data.

1. E. Browne, J. Tuli, Nucl. Data Sheets. 127, 191 (2015).
2. D. Ward, et al., Nucl. Phys. A 600, 88 (1996).
3. K. Abu Saleem, et al., Phys. Rev. C 70, 024310 (2004).
4. S. Zhu, et al., Phys. Lett. B 618, 51 (2005).
5. M. Bender, P.H. Heenen and P. Bonche, Phys. Rev. C 70, 054304 (2004).
6. B. Buck, et al., J. Phys. G: Nucl. Part. Phys. 34, 1985 (2007).
7. P. N. Usmanov, A. A. Solnyshkin, A. I. Vdovin, U. S. Salikhbaev, Phys. At. Nucl. 77, 1343 (2014).

Speaker: Pazlitdin Usmanov (Namangan Institute of Engineering and Technology)

18:20 K-FORBIDDEN M1-TRANSITIONS IN 156Gd

Analysis of the available experimental data obtained for the reactions , and at the nucleus, shows that almost all excited energy levels up to 2.0 MeV may be assumed to be uncovered [1]. The experimental data indicate the presence of a deviation from the Alaga rule. In particular, forbidden transitions from states of the band are observed.
In [2, 3], within the framework of the phenomenological model [4], which takes into account the Coriolis mixing of the states of the rotational bands, the low-lying states of the nucleus were studied. The energies, wave functions, and electrical characteristics of the states of the rotational bands were calculated. The reasons leading to the non-adiabatic effects, which manifest themselves in energies, wave functions of states, and ratios of transitions from vibrational states, are shown.
In the present paper we continue the study of the properties of the rotational states of the nucleus . We have calculated the reduced probabilities of transitions, using the wave functions obtained in [2]. The effect of rotation on the magnetic characteristics of excited states is studied. The calculated values of the probabilities of transitions from the states of the and bands are listed in the table and compared with the available experimental data.

1. C. W. Reich, Nucl. Data Sheets. 113, 2537 (2012).
2. P. N. Usmanov, E. K. Yusupov, IIUM Eng. J. 22, 167 (2021).
3. P. N. Usmanov, A. I. Vdovin, E. K. Yusupov, Bull. Russ. Acad. Sci.: Phys. 85, 1102 (2021).
4. P. N. Usmanov, I. N. Mikhailov, Phys. Part. Nucl. 28, 348 (1997).

Speaker: Pazlitdin Usmanov (Namangan Institute of Engineering and Technology)

17:10 → 19:00 Nuclear technology and methods in medicine, radioecology.

17:10 ADAPTIVE RADIATION THERAPY METHOD USING CONE BEAM COMPUTED TOMOGRAPHY

There are situations at prolonged treatment when patient loses weight, tumor changes its size or new lesions appear. In this case adaptive radiation therapy (ART) is necessary. This concept takes into account the changes of patients’ parameters and involves the recalculation of the treatment plans using new set of images. In this phantom study the ART method with using cone-beam computed tomography (CBCT) was developed.
CBCT doses for head and neck, chest and pelvis sites were calculated for small and big size of the heterogenic phantoms [1]. Deviation between the calculated CBCT doses and the reference doses was determined. The long-term stability of the ratio between Hounsfield Units and Relative Electron Density (HU-RED) for CBCT was investigated [2].
The deviation of the average dose in the target, for the plans on the CBCT with HU-RED for corresponding size and protocol, from the reference dose was less than 0.5 % and 1.5 % for pelvis and head and neck, respectively. For lung the deviation of the average dose in the target is 2 % from the reference dose only using the methods of the HU-RED correction.
HU-RED curves for XVI Elekta Synergy have good long-term stability.
The ART method using the CBCT was developed using X-Ray Volume Imaging (XVI) Elekta Synergy. This method allows to estimate consequences of pediatric patients’ anatomy changes and to recalculate new radiotherapy plans without additional scanning on the computed tomography (CT).

1. Dunlop A., McQuaid D., Nill S. et al. Comparison of CT number calibration techniques for CBCT-based dose calculation. // Strahlentherapie und Onkologie. 2015. V. 191. P. 970-978.
2. Rong Y., Smilowitz J., Tewatia D. et al. Dose calculation on kv cone beam CT images: An investigation of the HU-Density conversion stability and dose accuracy using the site-specific calibration. // Medical Dosimetry. 2010. V. 35. I. 3. P. 195-207.

Speaker: Dr A. Lisovskaya

Lisovskaya-nucleus-2022-1.docx

17:30 Determination of treatment efficiency of head-and-neck cancer based on TCP model

External beam radiotherapy based on volumetric modulated arc radiotherapy technic delivery is widely used for the treatment of the locally advanced head-and-neck cancer (LAHNC). There are some approaches of irradiation of LAHNC, for example, simultaneous integrated boost (SIB) and sequential boost (SEQ) [1]. Analysis of the developed treatment plans based on tumour control probability (TCP) models (Niemierko’s TCP model [2]) could help to estimate expected efficiency of the developed plans and to find optimal treatment schemes with respect to total dose value, fractional dose and overall treatment time (OTT).
In this study, the simultaneous integrated boost VMAT (SIB-VMAT) plans and sequential boost VMAT (SEQ-VMAT) plans were developed and ​​obtained values of TCP based on the anatomical data of 11 patients.
The anatomical data of 11 patients with LAHNC (larynx, oropharynx and oral cavity) were used. For each patient two treatment plans were developed, SIB-VMAT (70 Gy to tumour, 50 Gy to lymph nodes, 25 fractions) and SEQ-VMAT (70 Gy to tumour, 50 Gy to lymph nodes, 35 fractions). The developed plans were analyzed using the Niemierko’s TCP model with Maciejewski's parameters (TCD50=70.26 Gy) taking into account dose-volume histograms and OTT.
The developed SIB-VMAT and SEQ-VMAT plans had the physical coverage of the CTV tumours more than 97% of prescribed dose delivered to more than 97% of the volume, except one. The average TCP value of SIB-VMAT was equal to 99.9% due to short OTT. The average value of TCP for SEQ-VMAT was equal to 61.0%. For one patient, the both SIB-VMAT and SEQ-VMAT plans showed zero expected efficiency due to CTV coverage 95%-95%.
According to the Niemierko TCP model using Maciejewski's parameters, the 50% efficiency of the treatment could be reached at EUD equal to EUD = 70.26 Gy, when the prescription dose values higher than 71-72 Gy or 70 Gy delivered in less than 35 fractions. The analysis of selected clinical trials showed that the reported results of treatment efficiency rather well correspond to the model predictions. However, the results of DVHs calculated for real patients' anatomical data showed that even small volumes of the tumour that were irradiated to doses less than 70 Gy in 35 fractions could significantly decrease the expected TCP value. The results of simulation and analysis of clinical practice show that the DVH of each patient should be analyzed on the expected TCP.
1. Orlandi E, Palazzi M, Pignoli E, Fallai C, Giostra A, Olmi P. Critical Reviews in Oncology/Hematology. 2010; 73(2):111-125.
2. Maciejewski B, Withers HR, Taylor JMG, Hliniak A. International Journal of Radiation Oncology, Biology, Physics. 1989; 16(3):831-843.
3. Gay HA, Niemierko A. Physica Medica. 2007; 23(3-4):115-125.

Speaker: Dr E.S. Sukhikh

nucleus-2022-abstract_SukhikhES.docx

17:50 VERIFICATION PHANTOMS FOR DYNAMIC RADIOTHERAPY PLANS

Currently, verification phantoms for the verification of radiation therapy plans represents a rectangular or cylindrical solid body made of water-equivalent material with a rectangular hole for inserting a matrix detector. The most famous examples are the MULTICube phantom [1], which is a rectangular solid body made of plastic water (water equivalent with an error of ≤ 0.5%), which has several configurations, which allows you to install the MatriXX matrix detector [2] in the phantom body in a position corresponding to the region of interest; ArcCheck phantom [3], which is a cylindrical solid body made of polymethyl methacrylate with a built-in spiral grid of detectors, and having a cavity for inserts made of tissue-equivalent materials; Octavius 4D phantom which is a solid cylindrical body made of polystyrene (water equivalent with an error of ≤ 2%) with a rectangular hole in the center of the cylindrical phantom for inserting a matrix detector.
The analysis showed that a significant drawback of these devices is that their use for the verification of the patient's treatment plan does not give an accurate idea of the absolute dose values in the phantom volume (patient's body), since they use the cross-calibration coefficient and thus neglect a number of quantities that can affect the delivered absorbed dose.
The authors consider it expedient to develop a method for verifying radiation therapy plans, which makes it possible to improve the quality of verification of radiation therapy plans through the use of a cross-calibration coefficient determined taking into account the value of the radiation output of a medical linear accelerator immediately at the time of this procedure.

1. Access mode: http://test.scanditronix-wellhoefer.com/MULTICube.1362.0.html
2. Access mode: https://www.iba-dosimetry.com/product/matrixx-universal-detector-array/
3. Access mode: https://www.sunnuclear.com/products/arccheck

Speaker: Dr M.N. Petkevich

Petkevich nucleus 2022.docx

18:10 COMPARATIVE ANALYSIS OF DOSIMETRIC PLANS WITH SIMULTANEOUS DOSE ESCALATION FOR PROSTATE TUMORS IN THE APPLICATION OF BIOLOGICAL AND PHYSICAL OPTIMIZATION FUNCTIONS

Purpose of the work. a comparative analysis of radiation therapy (RT) plans with simultaneous dose escalation for prostate tumors in the application of biological and physical optimization functions.
Research methods. In this research, dosimetric plans with volumetric modulated arc therapy (VMAT) were developed for nine patients diagnosed with prostate cancer in the Simultaneous integrated boost (SIB) mode. RT was conducted in the following fractionation mode: the prescribed dose per course of radiotherapy for SIB was 75 Gy, the number of fractions was 25, so that the single focal dose was 3 Gy for PTV1 (prostate region), 2.5 Gy for PTV2 (prostate and seminal vesicles) and 2 Gy for PTV3 (prostate, seminal vesicles and regional lymph nodes) [1].
Dosimetric planning for SIB was performed in the Monaco environment (version 5.51.10) using VMAT. All the dosimetric irradiation plans had the same technical calculation parameters. Several therapeutic plans with different optimization functions were created for comparative analysis: physical; biological; a combination of physical and biological optimization functions. The acceptable level of prescribed dose was greater than 95% of the volume of each treatment site. A maximum dose of 107% of the prescribed dose was allowed for <2% of PTV1. Dose volume limits for OAR: for rectum: V74≤15%; V69≤20%; V64≤25%; V59 ≤35%; for bladder: V74≤25%; V69≤35%; V64≤50%; for femoral heads: V45<10% [2].
Results. The dose distribution in the clinical target volume for all VMAT-SIB plans was in the range of at least 95% of the prescribed dose covering at least 95% of the target volume. Radiation exposure levels to OAR did not exceed tolerated levels. A comparison of dosimetric plans showed that the best optimization of the PTV1 is achieved when only the physical functions are used. However, OAR receive less dose when only biological optimization functions are used.
Conclusion. The dose distribution results have shown that it is possible to create clinically acceptable dosimetric plans when only biological or physical optimization functions are used separately. Comparison of the obtained results shows that the most optimal dosimetric plan is achieved when using a combination of biological and physical optimization functions.

Speaker: Ms Ekaterina Selikhova (Master's degree from National Research Tomsk Polytechnic University)

nucleus-2022-abstract-Selikhova.docx

18:30 MEASURING THE RADIATION YIELD COEFFICIENTS OF SMALL FIELDS WITH IBA DETECTORS

The objectives of this work are: measurement of the data set of coefficients of radiative output (Output Factors - OF) using five detectors and data validation; determine how OF changes when using two types of field formation, namely, collimator shutters and a multileaf collimator (MLC); investigate the dependence of the output factors on the source-to-surface distance (SSD) and measurement depth, as well as on the type of detector used in the measurements.
The measurements were carried out in 6 MV photon beams with a smoothing filter on a TrueBeam linear accelerator. Five IBA detectors were used: two diode detectors (PFD and SFD) and three ionization chambers (CC 01, CC 04 and CC 13). Margins varied from 10cm x 10cm to 1cm x 1cm. Measurements were made with various combinations: SSD = 100cm and depth = 10cm, SSD = 95cm and depth = 5cm. The fields were formed by collimator shutters and MLC.
The radiation yield coefficient increases with decreasing SSD and measurement depth. An unshielded SFD diode detector has an insufficient response at low fields, a shielded PFD diode, on the contrary, has an excessive response. Ionization chambers have insufficient response at a field size of 1 cm x 1 cm due to their finite volume. At a field size of 1 cm x 1 cm, for any given SSD and depth, there is a large scatter in measured output factors between detectors. A particularly weak response in this field is observed in the CC13 ionization chamber with a volume of 0.13 cm3, which is largely due to the effect of volume averaging; this chamber is not suitable for measurements in such low fields.
To correct the output factors, it is necessary to use correction factors or calculate the coefficients based on the measurement results [1].

1. Dosimetry of Small Static Fields Used in External Beam Radiotherapy: An International Code of Practice for Reference and Relative Dose determination. / IAEA TRS 483, Vienna, 2017.

Speaker: Dr V.S. Piskunov

Piskunov nucleus 2022.docx

Wednesday, 13 July

10:00 → 11:30 Poster session: Applications of nuclear methods in science and technology

10:00 SiC Nuclear Radiation Detectors after Irradiation by Heavy Ions and Neutrons

Silicon carbide (SiC) is very perspective material for fabrication radiation-tolerant electronics, high-temperature electronics as well as for nuclear radiation detectors for working in harsh environments. SiC has obtained increasing interest due to achievement of a high purity level in the crystal structure and considerable thickness (> 100 µm) in the epitaxial layer. SiC is mostly investigated for its physical properties, e.g.: the band gap energy of the polytype 4H-SiC is 3.26 eV, the mean energy of electron-hole pair creation is 7.78 eV, the electron saturation drift velocity is 2 x 10^7 cm/s and the breakdown voltage is 2 x 10^6 V/cm at room temperature. Detectors based on high quality epitaxial layer of 4H-SiC show a high radiation hardness, good spectroscopic resolution and can operated not only at room but also at elevated temperatures (~300°C) [1,2].
Our detector structures [3] were prepared on a 25 µm or 50 µm thick nitrogen-doped 4H­SiC layer (donor doping < l x 10^14 cm-3) grown by the liquid phase epitaxy on a 4" SiC wafer (donor doping ~ 2 x 10^18 cm-3, thickness 350 µm). Circular Schottky Ni/Au contact (diameter 3.0 mm, thicknesses 10/30 nm) to 4H-SiC layer was formed through a contact metal mask, while full area Ti/Pt/Au contact (thicknesses 10/30/90 nm) was evaporated on the other side (substrate).
Electrical characteristic of prepared SiC detectors were measured using Keithley measuring complex, which consisted of 4200A-SCS Parameter Analyzer, 2657A High Power System and CVIV Multi-Switch. Current-voltage and capacity-voltage (C-V) measurements were performed up to 300 V. The reverse breakdown voltage exceeded 300 V and the reverse current was below 10 pA. From C-V measurements the depletion thickness and doping concentration profile were calculated. Spectroscopic parameters were measured with alpha sources 226Ra and 238Pu and FWHM of SiC detectors varied round of 20 keV for 5.5 MeV α-particles energy.
SiC detectors were irradiated by high-energetic beam of heavy ions of Xenon with energy of 165 MeV at the IC-100 cyclotron of the Joint Institute for Nuclear Research (JINR) in Dubna up to dose 1.5 x 10^10 cm-2. We also studied the effect of the degradation of these detectors under impact of neutrons at the neutron reactor IBR-2 (JINR) up to dose 3.4 x 10^15 cm-2.
Prepared SiC detectors shown good energy resolution and high radiation resistance against heavy ions and neutrons and will be used in experiments at JINR.

1. F.H. Ruddy and J.G. Seidel, NIM in Phys. Res. B 263, 163 (2007).
2. D. Puglisi and G. Bertuccio, Micromachines 10, 835 (2019).
3. B. Zat'ko et al., Applied Surface Science 536, 147801 (2020).

Speaker: Mr L. Hrubcin (JINR, IEE SAS)

Hrubcin-NUCLEUS 2022.docx

10:20 THE MEASUREMENT OF THE LOW LEVELS OF RADIOACTIVITY BY LIQUID SCINTILLATION ALPHA AND BETA SPECTROMETER QUANTULUS 1220

The Quantulus 1220 is a liquid scintillation counting (LSC) system for the quantitative measurement of extremely low levels of alpha and beta activity. With both passive and active shielding, the Quantulus 1220 employs a universal background reduction system which is optimized according to type of analysis.
The active shielding is the asymmetric liquid scintillator guard. The active shielding is used in anticoincidence with the analogue to digital converter (A/D converter). This means that if the guard registers a signal simultaneously with a coincidence signal in the detector the guard detector will inhibit the A/D conversion.
In the Centre of Isotopic Research (CIR) of FGBU "VSEGEI" Quantulus 1220 is used for radiocarbon (14C) dating of various organic objects (wood, peat, soil, bottom sediments, bones), dating young bottom sediments using 210Pb as well as determination the tritium content in water.
The minimum detectable concentration of tritium in water is approximately 1 Bq/L.
The obtained results are presented as the alpha and beta decay spectra of radioactive isotopes with calculations of the specific activities and radiocarbon ages.

Speaker: Konstantin Gruzdov

NUCLEUS-2022_ABSTRACT_GRUZDOV K.A._THE MEASUREMENT OF THE LOW LEVELS OF RADIOACTIVITY BY LIQUID SCINTILLATION ALPHA AND BETA SPECTROMETER QUANTULUS 1220.docx

10:40 THE APPROBATION OF ION-PLASMA TECHNOLOGY FOR REACTOR GRAPHITE DEACTIVATION

At present time a wide search of effective technology to deactivate reactor graphite is very acute due to the large volumes of accumulated irradiated graphite in the world (about 100 thousand tons) and the challenging problem of uranium-graphite reactors decommissioning period. The ion-plasma technology (IPT) for deactivation of reactor graphite has advantage compared with traditional radiochemistry in versatility (IPT works with any kind of radionuclides) and in the absence of the additional secondary liquid radioactive wastes (IPT buffer media is inert gas forming no chemical compounds with radionuclides). Our technology provides ion sputtering of irradiated reactor graphite surface in the “shortened” microplasma discharge in argon (it is wide known that the dose-forming 14С isotope is localized mainly inside of near-surface layers of reactor graphite blocks). The microplasma discharge is ignited between the reactor graphite (cathode) and the tantalum electrode collector (anode) under discharge parameters: current density (0.001 – 1) A/cm2), voltage (300-1000 V), argon pressure (0.01-1 atm.), discharge gap (1-5 mm). During reactor graphite treatment in the microplasma discharge, the graphite surface is sputtered and the sprayed carbon atoms are deposited on the anode surface. The results of SEM analysis of above microplasma exposed collector tantalum electrode surface (Fig. 1.) are concept proving and demonstrating workability of our ion-plasma technology.

Fig. 1. SEM image and X-ray microanalysis elemental composition of Ta anode surface.

Technology is patented in collaboration of Intro-Micro LLC, Concern Rosenergoatom JSC and Rosatom [1] and is also suitable for Fukushima NPPs accident dismantling efforts.
1. A.S.Petrovskaya, A.B.Tsyganov, M.R.Stakhiv, Patent RU №2711292, patent pending: International patent application PCT/RU2019/000816 (14.11.2019), entering national phase: US 20210272715, EP 19888171.6, CA3105179A1, CN112655056A.

Speaker: Dr Anna Petrovskaya (Plasma application department, InnoPlasmaTech LLC, St.Petersburg, Russia, Intro-Micro LLC, St.Petersburg, Russia)

Nucleus-2022-Abstract_Petrovskaya_Tsyganov_final.docx

11:00 Radiation resistance of SiC detectors under neutron irradiation

The results of an investigation of silicon carbide (SiC) detectors when irradiated with neutrons are presented. SiC detectors were manufactured on the basis of the epitaxial layer of 4H-SiC n-type conductivity. The thickness of n-type epitaxial layer was 50 µm. Schottky barrier contacts with a diameter of 3.0 mm were made by vacuum evaporation of a double layer of Ni and Au 10 and 30 nm thick. The initial energy resolution of detectors was < 25 keV for α-particles.
The radiation resistance of SiC detectors was studied experimentally by analyzing their characteristics before and after fast neutron irradiation with integral fluxes of 5.1x10^13, 5.4x10^14, 3.4x10^15 n/cm2. The irradiation was carried out at the pulse reactor IBR-2M (JINR, Dubna). The α-source 226Ra (E = 4.8, 5.5, 6.0, 7.7 MeV) that was used for calibration and control of spectrometric characteristics of SiC detectors.
It is shown that after neutron irradiation, significant degradation was observed: the peaks from the alpha particles shifted towards smaller channels and became much wider; with an increase in the flux, the energy resolution degrades by two, ten and twenty times; the charge collection efficiency (CCE) decreased from 100% to 96%, 70% and 1% (operating voltage 350 V) at the neutron irradiation fluxes of 5.1x10^13, 5.4x10^14, 3.4x10^15 n/cm2, respectively.

Speaker: Mr S. Evseev (DLNP JINR)

Nucleus-2022-Abstract-Evseev.DOCX

Poster_Nucleus_2022_EvseevSA.pdf

11:10 4π-METHODS FOR TOTAL REACTION CROSS SECTION MEASUREMENTS

A review and analysis of experimental 4π-methods for total reaction cross section σ$_{\rm{R}}$ measurements are presented. The methods for σ$_{\rm{R}}$ measurements are based on the 4π-technique of registering prompt γ-quanta and neutrons in a solid angle close to the full angle Ω = 4π.

The description the method applied to measuring γ-detection efficiency ε(M$_{{\gamma}}$) for various values of γ-multiplicity M$_{{\gamma}}$ are presented. The experimental facility and 4π scintillation spectrometer for M${_{{\gamma}}}$ measurement are described.

The comparison and analysis of the two experimental 4π-methods developed at FLNR JINR, Dubna for σ$_{\rm{R}}$ measurements in the reactions with neutron-rich weakly bound nuclei are presented. The first method is based on the mean value of the detection efficiency <ε> which does not depend on γ-multiplicity M${_{{\gamma}}}$ [1]. In the second method, we use the experimentally obtained response function ${w_M}\left( k \right)$ (the distribution of the numbers of triggered detectors k in registration of γ-cascade with a fixed value of M${_{{\gamma}}}$) [2].

1. Yu.E. Penionzhkevich, Yu.G. Sobolev, V.V. Samarin, and M.A. Naumenko, Phys. Atom. Nucl. 80, 928 (2017).
2. Yu.E. Penionzhkevich, Yu.G. Sobolev, V.V. Samarin, M.A. Naumenko, N.A. Lashmanov, V.A. Maslov, I. Siváček, and S.S. Stukalov, Phys. Rev. C 99, 014609 (2019).

Speaker: Sergey Stukalov (JINR, Dubna, Russia)

Stukalov2.docx

11:10 FLUCTUATIONS OF THE INDUCED CHARGE CAUSED BY FLUCTUATIONS OF THE X-RAY QUANTUM ABSORPTION POINT IN A PLANE-PARALLEL SEMICONDUCTOR DETECTOR

The book [1] provides a formula for fluctuations of the induced charge caused by the trapping of electrons and holes in the volume of a plane-parallel semiconductor detector, obtained in [2]. However, this formula was obtained for the case of a homogeneous distribution of X-ray quantum absorption points in the volume of the detector, and does not take into account the attenuation of the X-ray quantum flux as it penetrates into the detector. In [3], an attempt was made to take into account the attenuation of the X-ray quantum flux, but the formula published by the authors contains errors.
In this paper, formulae are obtained for the fluctuations of the induced charge on the detector electrodes caused by fluctuations in the absorption point of the X-ray quantum, taking into account the law of attenuation of the X-ray quantum flux. The obtained formulae demonstrate the role of covariance of induced charge on the detector electrodes caused by random processes occurring in the detector at the registration of X-rays.

1. A. Owens Compound Semiconductor Radiation Detectors, CRC Press (2012).
2. J. S. Iwanczyk, .W. F. Schnepple, M .J. Masterson, Nucl. Instr. Meth. in Phys. Res. A. 322, 421 (1992).
   3 A. Ruzin, Y. Nemirovsky, J. Appl. Phys. 82, 2754 (1997).

Speaker: Victor Samedov

Samedov_nucleus-2022-abstract-template.docx

11:10 INTERACTION OF SERUM ALBUMIN AND GRAPHENE OXIDE: INVESTIGATION BY TRITIUM PROBE AND MOLECULAR DOCKING

Graphene oxide (GO) modification with different compounds for synthesis of new materials with specified properties is the field of interest of modern investigation [1]. Since serum albumin is the main blood protein, it is important to understand the mechanisms of its interaction with medical materials. In present work we propose a novel complex approach of studying interactions between bovine serum albumin (BSA) and GO. The approach includes tritium probe method and computer simulation.
Tritium probe method is based on the application of tritium labeled compounds for the to determine the composition of composite materials, as well as to determine the structural organization of protein molecules on the surface of a solid substrate [2].
BSA was adsorbed on the solid of an aqueous suspension of GO. The composition of such prepared material was determined with the help of tritium labeled protein. We observed that BSA strongly adsorbs on GO. To reveal the structural peculiarities of protein on GO surface, the adsorption composite was subjected to bombardment with atomic tritium following by analysis of label distribution in the amino acid residues. Tritium atoms were formed from molecular tritium on the tungsten filament heated by the electric current up to 1830 K.
The experimental results were compared with molecular docking simulation. Molecular docking was performed using AutoDock Vina 1.2.3, LeDock and Hex8.0.0 softwires. Preliminary preparation of the carbon substrate model, minimization of the free energy of GO structure, as well as preparation of protein files for calculation were carried out using ChemBioDraw/3D Ultra 11.0.2., UCSF Chimera 1.15 respectively. The molecular modeling was performed tooking into account the presence of structural defects in GO, the hydrate shell on the surface of the nanocarbon substrate, as well as the formation of a "protein corona" due to protein-protein interactions.
As a result, we determined the composition of BSA-GO adsorption composites in the wide range of protein concentrations. Moreover, binding sites of BSA and GO have been identified, and the important role of histidine in protein retention on the GO surface will be discussed in the presentation.

1. Gusarova E.A. et al., Colloid and Interface Science Communications. 46, 100575 (2022).
2. Chernysheva M.G. et al., Radiochemistry. 63(2), 227 (2021).

Speaker: Vitalii Bunyaev (Moscow State University, Radiochemistry Department of Chemistry Faculty)

338-nucleus-2022-abstract-Bunyaev.docx

11:10 MULTIPARAMETRIC REGISTRATION SYSTEMS IN RADIOCHEMISTRY

This paper discusses aspects of the application of multiparametric ionizing radiation detection systems (MPSR) for the analysis of the composition of liquid radiochemical samples. Liquid active samples may occur, for example, in experiments or production processes of hydrometallurgy or activation analysis.
Currently, MPSR are not widely used in radiochemistry, but such a systems are successfully applied in nuclear physics, high-energy physics, biology, medicine. This is due not only to the high cost of such systems, but also for historical reasons. According to the authors, using of MPSR is becoming relevant for online monitoring at hydrometallurgical plants of a new generation, in experiments on radiochemical stands, activation analysis.
By MPSR we mean multi-detector registration systems in which signals coming from detectors are either continuously recorded on a data carrier and/or processed online. An important feature of such systems is the availability of temporary information. Devices called digitizers have become widespread for such systems, which record the signal coming from the detectors in the form of a continuous time series to the storage device, then processed offline. Another common method is to work in “list mode” for each channel, when the signal is pre-processed by classical methods of nuclear electronics and then only the signal amplitude and timestamp are recorded. In both cases, the signal can be represented as a set of amplitude spectra, as well as various coincidences. The paper proposes to use for these purposes the following set of scintillation detectors: beta-, two gamma-, X-ray detector, as well as an immersion silicon alpha detector. Mathematical data processing is supposed to be supplemented by digital filters. The paper discusses the decay schemes of various radionuclides, appropriate choice of detectors, the choice of methods of registration and mathematical processing. The exposure times estimated in trial experiments.

Speaker: Konstantin Ershov (ПИЯФ)

Ershov.docx

11:10 Position sensitive fast neutron detector based on the double-sided silicon strip detectors

A two-coordinate position-sensitive silicon detector of fast neutrons [1] was developed at Joint Institute for Nuclear Research (JINR), Dubna, Russia within the framework of the TANGRA (TAgged Neutron and Gamma RAys) project [2].
The detector is composed of four double-sided 300 µm thick silicon plates with the dimensions of 60×60 mm2 divided into 32x32 strips on both sides with strip's pitch of 1.81 mm. The X and Y strips of neighboring detectors are connected to each other, forming a single detector unit with 64x64 strips and 120x120 mm2 size.
To reduce the number of readout channels a special multiplexor electronics has been developed reducing the total number of readout channels to 6: one fast common start signal; four slow position channels (2 for each side) and one clock synchronization channel. The data from the detector are read out and analyzed by a multichannel 100 Mhz digitizer.
The performance of the detector was tested with a 256-pixel ING-27 generator of 14.1 MeV tagged neutrons, which made it possible to reconstruct a 2-dimensional map of the tagged neutron beams. It was also used for measuring the neutron beam profile with the energies of ~4 MeV generated in d-d reaction at the EG-5 accelerator.

Speaker: Askar Erbolot (JINR Dubna,Russia)

nucleus-2022-abstract-profilometer.docx

11:10 SEARCH CRITERIA FOR MINERAL DEPOSITS IN THE ZONES OF MODERN AND ANCIENT VOLCANISM ON URANIUM AND THORIUM AND THEIR FISSION PRODUCTS

In the work, by the method of gamma - spectroscopy [1,2], new data are presented on the deep recharge of the Nizhnechutinsk oil field by ascending gases and hydrotherms with different elemental composition. It has been established that formation waters, as well as oils, are enriched in As, Br, Ba, Re, Ir, Au, REE in the fluid replenishment zones. In this case, the greatest differences relate to the distribution of uranium and thorium over the area of the deposit and over the underlying oil reservoirs.
The results of the studies indicate the overlap and coexistence of deposits of hydrocarbons and ore minerals in the area of ancient volcanism, while the criteria for the influence of the manifestation of deep processes are both the well-known ratios of uranium and thorium (U/Th and/or Th/U) and the established we determined the values of the ratios Th/Ba, Mo/U, Ba/Mo.
The elements Ba and Mo are fission products of uranium and thorium. In this regard, we assume other types of mineralization, associated not with the release of magmas of different composition and post volcanic hydrotherms, but with known exhalation mineralization. According to our ideas, this type of mineralization is accompanied by a constant emanation of radioactive elements U, Th and elements of their radioactive decay along the zones of development of modern and paleovolcanic formations. At the same time, oils in the Upper Devonian deposits are enriched in a number of elements, the associations of which depend on the temperature of the ascending gas flows. Taking into account the results obtained, the search for deposits of solid minerals and hydrocarbons is carried out not only in terms of U / Th, but also according to the new criteria we have established - certain values of the ratios Th / Ba, Mo / U, Ba / Mo in the composition of rocks and accumulations of hydrocarbons.

Literature

1.Makarova I.R., Laptev N.N., Gorobets S.A., Valiev F.F., Yafyasov A.M., Sergeev V.O., Zippa A.I., Sukhanov N.A., Makarov D. .K., Grishkanich AS/ Application of methods of gamma spectroscopy and IR spectroscopy for the purposes of prospecting geology. Georesources, 2021, No. 1. – P.17 – 29.
2. Yafyasov A.M., Makarova I.R., Valiev F.F, Laptev N.N., Gorobets S.A., Sergeev V.O. / The application of gamma-spectrometry with a germanium detector for oil and ore geology // Bulletin of the Russian Academy of Sciences : Physics, 8 no. - T. 86. - 2022 (in print).

Speaker: Prof. Адиль яфясов (СПбгу)

11:10 SIMULATION OF THE FAST READOUT SYSTEM FOR MCP-BASED BEAM-BEAM COLLISIONS MONITOR FOR NICA EXPERIMENTS

The event-by-event selection of nucleus-nucleus interactions with well-defined initial conditions of the interaction point (IP) location in the experiment at NICA collider, beam-gas collisions suppression, precise event time definition, as well as control of luminosity, are important both for data collection and for the off-line analysis of the results of upcoming measurements at JINR. For these purposes, the compact Fast Beam-Beam Collisions Monitor (FBBC) based on the micro-channel plates (MCPs) was proposed recently in [1]. Position and time sensitive, multi-anode MCP detectors allow to get, for each bunch crossing, the information on the IP coordinate, on the multiplicity and of arrival times of charged particles formed in the collision.
In the present work, we estimate both the capabilities of the fast, precise timing measurements scheme and, in addition, of the collision centrality determination in AA collisions. The scheme is based on the method of delayed coincidences using high-speed comparators. We carried out the modeling of the system prototype within the framework of the Quartus [2] environment. Results allow us to state that it is possible to determine the response time of the detector with an uncertainty of about 50 ps. Using the coincidence schemes will make it possible to identify the number of spectators and, based on the processing of timing information, to make conclusions about the centrality of interaction in each event.
The estimated speed of the analysis scheme is less than 20 ns per each event. This allows us to propose this FBBC readout system, based on the high-speed comparators, as the fast, bunch-by-bunch crossing pre-trigger, both in terms of the IP position and the class of centrality.
This research has been conducted with financial support from St. Petersburg State University (project No 93025435).

1. A.A. Baldin et al., Nucl. Instrum. & Meth. A. 958 . 162154 (2020).
2. Intel Quartus Prime Design Software, https://www.intel.ru/content/www/ru/ru/software/programmable/quartus-prime/overview.html

Speaker: Mr nikodim makarov (saint-petersburg state university)

Thesis-fast pretrigger.docx

11:10 STUDY OF SORPTION PROPERTIES OF MODIFIED STRUCTURAL MATERIALS FOR NUCLEAR POWER ON GAMMA-QUANTUM BEAMS OF LINEAR ACCELERATOR

The energy crisis is currently one of the pressing global problems. And one of the solutions to this problem is the use of a highly efficient resource - nuclear energy. The use and development of this resource is constrained by the safety factor in the operation of nuclear reactors. Today, concrete is widely used as a material for radiation protection: it is cheap, it is easy to form structures of various shapes, and it is a good absorber [1]. Radiation shielding concrete is a composite with special fillers. It is widely used for shielding against gamma rays and neutrons due to its good shielding properties and is the biological barrier of choice in nuclear reactors and other nuclear installations. However, despite this, the process of radiation damage to cement, which is part of concrete, and the effect of different concentrations of chemical elements on its radiation resistance are still insufficiently studied. Therefore, the study of materials used to provide radiation protection is an actual direction.
In this work, studies were carried out on three samples of cement with different contents of $B_4C$, $Fe_3O_4$ and $BaSO_4$. To study the coefficients of linear absorption of gamma quanta in the samples under study, an Elekta Axesse electron accelerator with gamma quanta energies of 10 and 15 MeV was used as a source of gamma quanta. The samples were made at Cairo University (Egypt). To obtain the linear attenuation coefficients of the samples, the technique developed earlier by the authors was used [2].
As a result, experimental linear attenuation coefficients for samples with various impurities were obtained, and it was shown that cement with a high $BaSO_4$ content is a good absorber of 10 and 15 MeV gamma quanta. However, such samples must be studied for radiation resistance from neutron radiation.
This research is funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP09058404).

1. A. Makarious, I. Bashter, E. Abdo, M. Azim, and W. Kansouh, Ann. Nucl. Energy 23(3), 195 (1996).
2. Y. Zaripova, T. Gladkikh, M. Bigeldiyeva, V. Dyachkov, and A. Yushkov, Reports of NAS RK 5, 126 (2021).

Speaker: Yuliya Zaripova (al-Farabi Kazakh National University)

Zaripova_3.docx

11:10 TOF MEASUREMENT OF LOW-ENERGY NEUTRON SCATTERING BY DEFORMED NUCLEI

The measurement of cross sections for neutron scattering by deformed nuclei in the energy range from 1 keV to 3 MeV is possible on the time-of-flight (TOF) channel of a pulsed neutron source based on a linac proton beam trap. The use of a beam with a duration of 0.3 μs will make it possible to measure neutron cross sections in this energy range with a resolution of (1–30)% over a 50 m span. Using elastic neutron scattering on W sample, the neutron spectrum was measured in the TOF channel of a pulsed source at an accelerator beam current of 1 μA
Measurement of the inelastic neutron scattering cross section at the threshold of excitation of rotational states of deformed nuclei up to 0.5 MeV is relevant for nuclear power engineering. When calculating the dynamics of nuclear reactors, it is necessary to take into account the energy dependence of the neutron strength functions of nonspherical nuclei, which can be determined from the measured total cross sections in the range from 1 keV to 2 MeV.

Speaker: Dr Vladimir Skorkin (INR RAS)

3 poster-abstract-TOF_skorkin.doc

id #348_ poster_TOF_Sk.pptx

10:00 → 11:30 Poster session: Design and development of charged particle accelerators and ionizing radiation sources

10:00 COMPACT NEUTRON CALIBRATION SOURCE BASED ON 252Cf RADIONUCLIDE AND A SILICON SEMICONDUCTOR DETECTOR

This work will demonstrate the operation of a model of compact neutron calibration source. Compact neutron calibration source is highly needed for calibration and response function determination of WIMP-oriented dark matter detectors and electron antineutrino detectors. This could be done with neutron calibration source with either known neutron energy spectrum, or by time-of-flight (ToF) neutron energy reconstruction.
Suggested neutron calibration source is based on Californium-252 radionuclide which undergoes spontaneous fission producing neutrons with a continuous spectrum and a semiconductor detector. The latter upon registration of fission fragments signal provides a time reference of the moment of neutron creation.
For registration of the fission fragments signal we used a silicon semiconductor detector with thin entrance window. Performed investigations have proved that such a detector may withstand exposure of up to 10^9 of fission fragments before the critical degradation of its operating parameters occurs [1]. The spectra of neutrons and γ-quanta produced during the spontaneous fission of 252Cf nuclei were recorded with help of PMMA scintillator equipped with photomultipliers of type 97. The scintillator represents a cylinder with a wall thickness of 7 cm and an internal diameter of 13 cm. In the center of scintillator cylinder a 252Cf source and a semiconductor detector were placed.
These two registration channels for neutrons and fission fragments, respectively, operates in the coincidence mode in order to establish the correlation between the fission fragments and neutron / γ-quanta signals, which, in turn, can be separated by accounting the delay time of the neutron arrival. Therefore, the possibility of using a combination of the semiconductor detector and 252Cf radionuclide as a compact neutron calibration source will be demonstrated.

1. S.V. Bakhlanov, A.V. Derbin, I.S. Drachnev, O.I. Konkov, I.M. Kotina, A.M. Kuzmichev, I.S. Lomskaya, M.S. Mikulich, V.N. Muratova, N.V. Niyazova, D.A. Semenov, M.V. Trushin, E.V. Unzhakov, Journal of Physics: Conference Series 2103, 012138 (2021).

Speaker: Dr Maxim Trushin (NRC "Kurchatov Institute" - PNPI)

156-nucleus-2022-abstract-Trushin_1.docx

Poster-2022_Trushin2.pdf

10:20 FOURIER-IR SPESTROSCOPIC STUDIES OF n-C6H14 AND n-C6H14 + H2O SYSTEMS

Radiation-catalytic processes for the production of molecular hydrogen from a mixture of hexane and hexane-water It is of great interest to discover new ways of conversion and use of ionizing radiation for the production of molecular hydrogen, which is a universal energy carrier. The results of the research may be important to clarify the mechanism of the processes that occur under experimental conditions under the influence of ionizing radiation in the hexane, hexane-water system, as well as under natural conditions in oil and gas fields under the influence of natural radionuclides.
In the presented work, Fourier-IR spestroscopic studies of n-C6H14 and n-C6H14 + H2O systems were performed. The results of spectroscopic studies suggest that the ratios of the intensities of the absorption bands characterizing the CH2, CH3 groups vary depending on the dose rate (valence and deformation oscillations of CH2 and CH3 are 2800 - 2970 cm-1 and 1300 - 1500 cm-1, respectively. 1 are located in the spectral regions). Absorption bands - (CH2) belong to the long chain type of type n (n4) and CH2 lattice oscillations (spectral region  = 650 - 850 cm-1). During radiolysis of the n-hexane + water system (3:1) after gamma radiation, 5 new bands are observed in the frequency range  = 2600 - 2700 cm-1, which indicates that the decomposition of n-hexane produces heavier paraffin during radiation-chemical processes. - The change and distribution of the maximums and intensities of absorption bands in the chain region of (CH2) ( = 650 - 850 cm-1) indicates the formation of paraffins of type C1 - C5. The formation of C1 - C5 products is confirmed by the spectra of gases in the system under study. The decomposition of water in the studied system is followed by the formation of absorption bands of OH-groups in the spectra in the frequency range  = 3000 - 3600 cm-1 (valence region),  = 1700 - 1600 cm-1 (deformation region). The formation of olefins as a result of radiolysis of the n-hexane + water (3:1) system was not observed in the IR spectra.

Speaker: Dr Sevinj Melikova

Melikova_tezis.docx

10:40 INVESTIGATION OF SECONDARY ELECTRON EMISSION PROCESSES IN ACCELERATOR CHARGED PARTICLE BEAM MONITORING SYSTEMS

Today, charged particle accelerators play an important role for the study of the nuclei structure, elementary particle physics and for the production of radionuclides used in medical technologies. An important condition for these accelerators operation is to improve the quality of the extracted beams. Therefore, one of the main instruments of accelerator and beam technologies are the systems for charged particle beams diagnostic, which make it possible to obtain information about the main parameters of the beam: beam profile, beam current, beam emittance. To monitor charged particle beams and increase their intensity on the targets are often use sensors. The operation of such sensors based on secondary electron emission processes. In this work, the monitoring system for charged particle beams (consists of a scanning gold-plated tungsten wires grid and placed inside of the accelerator beam pipe) is discussed. The beam particles interact with the wires and knock out secondary electrons. As a result, each wire becomes a current generator and current is proportional to the intensity of the beam particles. By measuring the current from each wire, one can reconstruct the beam profile and investigate the secondary electron emission processes.
In present work the mechanisms of current distributions caused by space charges of secondary electrons formed during the passage of heavy ion and proton beams (used cyclotron of the A.F.Ioffe Institute, Russian Academy of Science) through a grid of thin scanning wires were studied. Also a model for the visualization of the beam profile was developed, and the main parameters of secondary electron emission processes with beam intensity were determined.

Speaker: Dr E. O. Zemlin

Zemlin_Abstract_nucleus-2022.docx

10:40 The effect of the "FLAT-TOP" resonant system of the DC-280 accelerator on the accelerated ion beam

The work was carried out, during which the effect of the additional accelerating system "flat-top" on the beam of accelerated ions was studied and verified. This technology makes it possible to reduce the energy spread in accelerated ion clumps and implement an effective single-turn output, which consequently increases the efficiency of beam transmission.

Speaker: Павел Игоревич

382-Nucier-2022-abstract-Vinogradov.docx

10:00 → 11:30 Poster session: Experimental and theoretical studies of nuclear reactions

10:00 NEUTRON SCATTERING ANALYS BY LIGHT NUCLEI USED COUPLED CHANNEL OPTICAL MODEL

At present, an optical-model analysis of the scattering of nucleons by light nuclei, which have a cluster structure and collective states, is used.
We have calculated the cross sections of fast neutron scattering on even-even nuclei of 1p shell used by rotational variants of CCOM. Nuclei with an unfilled 1p-shell are deformed and have a non-uniform nucleon distribution density.
The cross sections of elastic and inelastic scattering of neutrons by even isotopes of helium, beryllium, carbon, and oxygen with the excitation of rotational states of these nuclei were calculated.

Speaker: Vladimir Skorkin (INR RAS)

2 poster-abstract-RCCOM_skorkin.doc

id #352_ poster_Sk.pptx

id #352_Sk.pptx

10:20 DETERMINATION OF THE ASYMPTOTIC NORMALIZATION COEFFICIENTS FOR $^7$Li+p→$^8$Be FROM THE PERIPHERAL DIRECT CAPTURE $^7$Li(p,γ)$^8$Be REACTION AND THE ASTROPHYSICAL S FACTOR AT LOW ENERGIES

The reaction $^7$Li(p,$\gamma$)$^8$Be is part of the pp-chain in the Sun, leading to the formation of $^8$Be. In the present work, the analysis of the experimental astrophysical S factors S$^{exp}$(E) for the nuclear-astrophysical $^7$Li(p,$\gamma$)$^8$Be reaction in the off-resonance energy region measured in [1] are performed within the modified two body potential approach [2], and assuming that, in this energy region ($E\le200$ keV) radiative proton capture by $^7$Li nucleus is direct.
The method involves two additional conditions that verify the peripheral character of the direct radiative capture reaction $^7$Li(p,γ)$^8$Be in the off-resonance energy region: 1) $R(E,b)=const$ for arbitrary variation of the single particle asymptotic normalization coefficient b for each fixed experimental value of the energy $E$; 2) the ratio $C_{p^7Li}^2=S^{exp}(E)⁄R(E,b)$ must not depend neither from $b$ and nor from the energy $E$ for each experimental point of the energy ($E$=98.3, 147.6 and 198.3 keV), where $R(E,b)=S^{(sp)}(E)⁄b^2$ in which $S^{(sp)}(E)$ is a single-particle astrophysical $S$ factor. Fulfillment of the conditions above, it allows to determine “experimental” values of ANCs $C_{p^7Li}^2 [=(C_{p^7Li}^{exp})^2]$ for ground and first excited states of $^8$Be with their uncertainty. The obtained values of ANCs $(C_{p^7Li}^{exp})^2$ can be used in the expression $S(E)=(C_{p^7Li}^{exp})^2 R(E,b)$ for obtaining the extrapolated values of $S(E)$ and its uncertainties within the energy range $E< 98.3$ keV, including $E=0$.
Variation of values of the parameters of the Woods-Saxon potential $r_0$ and $a$ is done in the wide range ($1.1\le r_0 \le 1.4$ fm, $0.59\le a \le 0.72$ fm) and it is shown that the reaction is strongly peripheral. As a result, the new values of ANCs $(C_{p^7Li}^{exp})^2$ with their uncertainties for $^7$Li+p→$^8$Be were obtained. The obtained values of ANCs are used for calculation of the astrophysical S factor of the radiative resonance capture $^7$Li(p,$\gamma$)$^8$Be reaction within the modified R-matrix method [3].

1. D. Zahnow, C.Angulo, C.Rolfs, S.Schmidt, and et al., Z. Phys. A 351, 229-236 (1995).
2. S.B. Igamov and R.Yarmukhamedov, Nucl. Phys. A 673, 509 (2007).
3. K.I. Tursunmakhatov, R.Yarmukhamedov and S.B.Igamov, EPJ Web of Conf. 227, 02016 (2019).

Speaker: Kakhramon Tursunmakhatov (Institute of Nuclear Physics, Academy Sciences of Uzbekistan)

Tursunmakhatov_Nucleus_2022.docx

10:40 A METHOD OF GAMMA-SPECTRUM PROCESSING BASED ON EXPONENTIAL SMOOTHING

This paper proposes a new method to smooth out the spectral gamma-lines. Calibration samples supplied with the gamma spectrometer containing radioactive isotopes Eu152, Co60 and Na22were used as test objects. The position, width and area of the peaks obtained as a result of spectrometry characterize the energy and intensity of gamma radiation. As is known, these peaks are superimposed on a continuous spectrum of energy resulting from secondary effects and background radiation [1].
The smoothing procedure was performed using interpolation by the system of uniform shifts of the Gaussian function [2]:

Since the standard interpolation procedure becomes highly unstable with increasing variance [3], regularization was applied. Results of the simulation indicate that the proposed method for filtering spectral lines does not introduce distortions into the original signal. On the other hand, the representation of spectral lines as a linear combination of Gaussian function shifts provides an additional opportunity for analytical calculations with a given signal during subsequent more detailed processing.
It is not necessary to pick the form of the peaks because they are represented as a sum of several shifts of the Gauss function with various amplitudes. As a result, a more versatile peak detection system has been obtained that does not require serious changes from one type of signal to another. A feature of the proposed method is that the peak areas for the original and smoothed signal may differ by around 10%, but with a significant change in the variance of the regularization parameter the area changes are small, which ensures the calculation robustness.

1. R. Gordon Gilmore .Practical Gamma-ray Spectrometry.2nd Edition. –Nuclear Training Services Ltd, John Wiley &Sons , Warrington, UK, 2008.
2. V.Maz'ya, G. Schmidt, AMS Mathematical Surveys and Monographs, 141, 350 (2007).
3. E.A.Kiselev, L.A.Minin, I.Y.Novikov and S.M.Sitnik, Math. Notes 96, 228, (2014).

Speaker: Dr Leonid Minin (Voronezh State University)

Минин Тезисы апрель 2022_v2 - перевод.docx

11:00 Computer Simulation of PFN Detector

PFN emission of 235U(n,f) reaction are under investigation in JINR for last 20 year. The recent achievements in experimental apparatus simulation are the subject of this presentation. The object of simulation is prompt fission neutron (PFN) detector used for resonance neutron induced fission of U-235. The neutron source was IREN facility and double ionization chamber (DIC) with Frisch grids was used for fission fragment spectroscopy. The PFN detector was multi detector system consisted of 32 BC501 scintillation liquid filled modules from the Sionix (Netherlands) company. Detectors were located on the sphere surface with 50 cm radius. Double Frisch gridded ionization chamber, used as fission spectrometer at the same time generated trigger signal for PFN registration apparatus. For each fission event the following simulated information was recorded: correlated fission fragments time mark, emission angle in respect to the selected coordinate frames along with the pulse heights and shapes of neutron detector signals. Multiple neutron scattering and the cross-talks were taken into account in order to evaluate contribution of those effects in the final results.

Speaker: Olga Sidorova (Joint Institute for Nuclear Research)

345-nucleus-2022-abstract-Sidorova.docx

11:10 6Li(d,alpha)4He REACTION CROSS SECTION EVALUATION IN 0-20 MeV DEUTERON ENERGY RANGE

New evaluation of 6Li(d,alpha)4He reaction integral cross sections (fig.1) was performed at our SaBa library [1]. Our data obtained from measured differential cross-sections [2, 3] at 3.75-8 MeV deuteron energy were used for evaluation. Astrophysical S-factor evaluated value at zero deuteron energy was (24370±269) MeV•mb.
1. A.G.Zvenigorodskij, V.A.Zherebtsov, L.M.Lazarev et al., The library of evaluated and experimental data on charged particles for fusion application, IAEA-NDS-191, 1999.
2. L.N. Generalov et al., Proc. LXIX Int. Conf. on Nucl.Spect. and Nucl.Struct.“Nucleus-2019”. Dubna. 116 (2019).
3. L.N. Generalov et al., Bull.Russ.Acad.Sci.Phys. 84, 1511 (2020).

Speaker: Ms S. M. Selyankina (Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics)

abstract_6Li(da)_4_eng.doc

11:10 CHARGE DISTRIBUTIONS FOR NUCLEI-ISOBARS DURING 238U PHOTOFISSION

An experimental and theoretical study of the charge distribution for isobar nuclei during photofission of 238U nuclei has been carried out. To study fragments of photofission of 238U nuclei, a gamma-activation method was used, that is, a method in which the radioactivity induced in the target by a beam of γ-quanta from an accelerator is analyzed. An experiment on the irradiation of a uranium target was carried out on the bremsstrahlung of the RTM55 accelerator of the Institute of Nuclear Physics, Moscow State University, with a beam energy of 55 MeV. The charge distributions of fission fragments were obtained for chains of nuclei with mass numbers: 131,132,133 and 139. The results obtained in the experiment were compared with the results of work performed on bremsstrahlung beams of gamma quanta and proton beams and hypotheses of unchanged charge distribution (UCD) and minimum potential energy (MPE).
The most probable Zp charges obtained experimentally, as well as deviations from the predictions of the UCD and MPE models, are presented in Table 1 below.

А Zp(exp) Z(UCD) Zp-Z(UCD) Zp(MPE)
131 51,102±0,271 51,068 0,035±0,271 50,428±0,057
132 51,290±0,101 51,457 -0,167±0,101 51,153±0,064
133 51,530±0,209 51,848 -0,317±0,209 51,768±0,140
139 54,125±0,001 54,186 -0,061±0,001 54,131±0,072
Table 1. Comparison of experimental and theoretical values of the most probable charge for chains of nuclei with mass numbers 131, 132, 133, and 139.

Speaker: Aleksander Kuznetsov (Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia; Faculty of Physics, Lomonosov Moscow State University, Russia)

nucleus2022_06_charge_distribution U.docx

11:10 Computer modeling of ttH Higgs boson production process in the framework of MSSM model

The properties of the MSSM Higgs bosons, h and H, through the comparison with the actual experimental data were studied. For such appropriate investigation ATLAS data of the cross sections of Higgs boson decay into b-quarks were considered. In the framework of theoretical research of modeled process the tree-level Higgs sector described by two parameters M$_A$ and tan$\beta$ was used and their optimal values were found. Using the restricted parameter space we calculated cross sections of associated tth(H) production at 13 and 14 TeV, the corresponding kinematical cuts, mass distributions and Branching Ratios of h and H decays into bb quark pair.

Speaker: Dr Tetiana Obikhod

11:10 DEPENDENCE OF THE CONVERSION WIDTHS ON THE FINE STRUCTURE OF THE ELECTRON SHELL

**Usually internal conversion (IC), and IC coefficients (ICC) in particular, are considered under the assumption of a closed shell of the initial atom. Its angular momentum is then zero. As a rule, this approximation is sufficient for the purposes of experiment in neutral atoms or ions of low multiplicity. However, modern experiments on storage rings, for example, in GSI or Lanzhou, are carried out with few-electron ions, for example, with helium (He)- or lithium (Li)-like ones. In this case, the electron shell has an angular momentum other than zero, which will certainly affect the probability and coefficient of the IC. To illustrate, consider as an example a E2 transition of a nucleus from the initial excited state with spin I1 = 2 to the final state with spin I2 = 0 in a beryllium-like ion 1s22s2p1/2. Then the total momentum of the electron shell J1 can take on the values J1 = 0 or 1, and the conversion probability on the 2p electron will be proportional to 2J1+1. A similar conclusion can be drawn in the case of the Li-like initial configuration 1s22p1/2. As a result, the conversion probabilities and, accordingly, the ICC in these states will be related as 1 : 3 : 2, respectively. The issue of total angular momentum is of fundamental importance in the case of a reverse IC (NEECxe [1]). The report develops the theory of the question as applied to the conventional and inverse IC.

1. F. F. Karpeshin, M. B. Trzhaskovskaya, C. Brandau. Reverse Conversion in $^{161}$Dy Ions as an Extension of Dielectronic Recombination. Izv. RAN, Ser. Fiz., 78, 891 (2014) [Bull. Russian Acad. Sci., Physics, {\bf 78}, 672 (2014)].
   **

Speaker: Feodor Karpeshin

ICC.docx

11:10 DESCRIPTION OF CHARGE-EXCHANGE REACTIONS IN TIME-DEPENDENT 2D MODEL

The experimental data on the charge-exchange reactions ${}^{45}$Sc(${}^{3}$He,t)${}^{45}$Ti, ${}^{194}$Pt(${}^{3}$He,t)${}^{194}$Au [1, 2] requires development of microscopic models of such processes. The microscopic approach based on the time-dependent Schrödinger equation for the wave function of the independent nucleons [3] does not take into account proton-neutron interaction and correlations. Simultaneous transfer of a proton from the projectile nucleus to the target nucleus and transfer of a neutron in the backward direction is studied using quantum two-body two-dimensional (2D) time-dependent model [4].

1. N.K. Skobelev, A.A. Kulko, Yu.E. Penionzhkevich, E.I. Voskoboynik, V. Kroha, V. Burjan, Z. Hons, J. Mrazek, Š. Piskoř, and E. Šimečkova, Bull. Russ. Acad. Sci.: Phys. 77, 795 (2013).
2. N.K. Skobelev, Yu.E. Penionzhkevich, E.I. Voskoboinik, V. Kroha, V. Burjan, Z. Hons, J. Mrazek, Š. Piskoř, E. Šimečkova, and A. Kugler, Phys. Part. Nucl. Lett. 11, 114 (2014).
3. V.V. Samarin, Yu.E. Penionzhkevich, M.A. Naumenko, and N.K. Skobelev, Bull. Russ. Acad. Sci.: Phys. 82, 637 (2018).
4. V.V. Samarin, and S.M. Samarina, Surface Investigation 14, 621 (1998).

Speaker: Viacheslav Samarin (Joint Institute for Nuclear Research)

2Samarin_nucleus-2022-abstract-charge-exch1.docx

11:10 DIFFRACTION PROCESSES IN 12-C ELASTIC SCATTERING BY MEDIUM NUCLEI

The study of multicluster structures of a nucleus is an urgent task due to the fact that the influence of cluster states, both excited and ground, rather strongly affects the properties of the nuclei under study. In the framework of the diffraction theory and under the assumption of complete absorption inside the interaction sphere, in this work, the authors obtained expansions of the total amplitudes of the angular distributions of the differential cross sections for elastic scattering of 12-C on nuclei up to 40-Ca. The study of such diffraction processes using the method [1] makes it possible to reveal the partial scattering amplitudes and their contribution to the total amplitude, which characterize the multicluster structure of the nucleus. For a comprehensive analysis of the multicluster structure of nuclei, the authors of [2] proposed an experimental method for the direct detection of cluster structures in the nucleus. The available world experimental data are described within the framework of the method. This method showed itself well in the study of alpha-cluster 4n nuclei. However, for 4n±1 nuclei, a third component was added to the total amplitude [1]. This modification of the method made it possible to describe a larger range of light atomic nuclei. Until now, only incident alpha particles have been analyzed. In [3], the authors performed an analysis of the angular distributions of the differential cross sections of elastically scattered 16-O on 4n nuclei, which fairly well described the experimental data up to 40-Ca.
In this work, the authors chose 12-C as the incident particles. As a result, an analysis of the differential cross sections of elastic diffraction scattering of 12-C on medium nuclei at energies from tens to hundreds of MeV was performed using a modified method of angular distributions. From a systematic analysis of the previous and results of this work, it was obtained and shown that clusters with characteristic radii of 1 fm and 0.5 fm are mainly detected.
This research has been funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP09258978).

1. V.V. Dyachkov, K.S. Dyussebayeva, Yu.A. Zaripova and A.V. Yushkov. Phys. At. Nuc. 83(12). 1705 (2020).
2. Yu.A. Zaripova, V.V. Dyachkov, A.V. Yushkov, T.K. Zholdybayev and D.K. Gridnev. Int. J. Modern Phys. E. 27(2). 18500171 (2018).
3. V.V. Dyachkov, Yu.A. Zaripova, A.V. Yushkov and M.T. Bigeldiyeva. Book of abstracts “NUCLEUS – 2021”. 306 (2021).

Speaker: Dr Vyacheslav Dyachkov (al-Farabi Kazakh National University)

nucleus-2022-abstract-1_corr.docx

11:10 Effect of double spin-orbit parameters on fusion barrier of prolate-prolate deformed nuclei

Relativistic mean-field model (RMF) and Skyrme Hartree fock (SHF) approach with effective energy functionals are applied to describe the bulk properties of nuclei. However, SHF model with standard parametrization fails to address the charge isotope shifts in the vicinity of major shell closures [1], which on the other hand is well described by the RMF model calculations [2]. This contrariety is related to the peculiarity of the spin-orbit (S-O) interaction potential (VJ) and hence corresponding modifications are required in SHF functional. In view of this, a simple generalization of the Skyrme functional is considered with a larger flexibility within the spin-orbit term by means of an additional coefficient W0term along with W0. Subsequently, six parameterizations of the Skyrme functional such as SkIx (x=1 to 5) [3] and SAMi [4] are obtained. In the present work, out of six forces, four different parameter sets are chosen such as SAMi (W0=137; W0 =42), SkI4 (W0=183.09; W0= -180.35), SkI3 (W0=94.25; W0=0) and SkI2 (W0=60.301; W0` =60.301) and their effect in terms of double spin-orbit strength is examined in the fusion dynamics of 90Zr+90-96Zr reactions. The explicit dependence of deformation effect is incorporated by taking prolate-prolate target-projectile combinations. The study is carried out within the framework of Skyrme energy density formalism (SEDF) [5] by calculating the change in fusion barrier height (ΔVB=VB (with VJ)-VB (without VJ)) of considered reactions. It is observed that independent of the reaction channel, maximum decrease in the fusion barrier height is obtained with SAMi force (having greater influence of S-O term) followed by SkI4, SkI3 and minimum with SkI2 Skyrme force. Moreover, the effect of target deformation is such that the value of ΔVB is maximum for 90Zr+96Zr reaction having strong deformation dependence (β2P=0.035; β2T=0.217) and minimum for weakly deformed combination i.e., for 90Zr+90Zr channel (β2P=0.035; β2T=0.035). This means that the double spin-orbit parameters of the spin-orbit strength along with deformations of interacting nuclei significantly affect the fusion barrier height of considered reactions. In further study the relative influence of these Skyrme forces will be analysed on fusion excitation functions and the results will be presented during the conference.
Dr Rajni gratefully acknowledges the financial support from the CSIR, New Delhi, India (file no. 09/1007(13391)/2022-EMR-I).
1. N. Tajima, P. Bonche, H. Flocard, P.-H. Heenen, and M.S. Weiss, Nucl. Phys. A 551, 434 (1993).
2. M. M. Sharma, M. A. Nagarajan, and E. Ring, Phys. Lett. B 312, 209 (1993).
3. P.-G. Reinhard and H. Flocard, Nucl. Phys. A 584, 467-488 (1995).
4. X. Rocka-Maza, G. Colo, and H. Sagawa, Phys. Rev. C 86, 031306 (R) (2012).
5. Rajni, D. Jain, I. Sharma, and M. K. Sharma, Eur. Phys. J A 53, 208 (2017).

Speaker: Dr Rajni Mittal (Department of Physics, SVNIT Surat Gujarat)

nucleus-2022-abstract.docx

11:10 ELECTRON AND POSITRON SPECTRA FROM PAMELA BY MULTIVARIATE DATA ANALYSIS METHODS

For 10 years, since 2006 to 2016, PAMELA, a satellite-borne experiment, had been conducting measurements of cosmic rays [1]. Currently, one of the open problems is researching cosmic-ray electron and positron energy spectra, also their time dependencies. The apparatus is estimated to measure these spectra combined from 50 MeV up to 1–2 TeV (600–700 GeV to determine the sign of charge) [2,3]. By the moment, the PAMELA collaboration has published results on 2006–2009 electrons and positrons spectra [3,4], complementing which with the data for the rest period of the measurements with the PAMELA instrument is the priority goal of the ongoing work.

This work presents a new approach to processing the PAMELA experimental data, and preliminary results obtained using it. Besides the previously used complex analysis of parameters extracted from the detectors systems, particular attention is given to machine learning methods to process this data. As such a tool, the TMVA package of the ROOT software is used [5], which is applied for multivariate data analysis. By means of preliminary program training on the test sets of parameters derived from modeling electrons and positrons passing though the PAMELA detectors with GEANT4 package [6], this method enables optimizing the experimental data processing while raising its selection efficiency due to the 1.5 times, compared to the ones obtained before. As an example of the application of the method, this approach has been used to obtain the electron and positron fluxes and their time dependencies, such as the flux ratios of positrons and electrons, positrons and protons, for the whole PAMELA data collection period.

1. O. Adriani et al., La Rivista del Nuovo Cimento 10, 473–522 (2017)
2. P. Picozza et al., Astroparticle Physics 27, 296–315 (2007)
3. O. Adriani et al., Physical Review Letters 106(20), 201101 (2011)
4. O. Adriani et al., Physical Review Letters 111(8), 081102 (2013)
5. https://root.cern/manual/tmva/
6. https://geant4.web.cern.ch/

Speaker: Павел Мухин

Mukhin+Mikhailov_Poster.pdf

nucleus-2022-abstract-Mukhin+Mikhailov.docx

11:10 HIDDEN VARIABLES IN ANGULAR CORRELATIONS OF FISSION PRODUCTS

The hidden-variables (HV) theory was once put forward by opponents of the probabilistic interpretation of the wave function (EPR paradox). It was assumed that the state of the system could be predicted with a less uncertainty than this is admitted by the Heisenberg uncertainty principle, if one knew additional, that is HV. This theory is rejected by the community. However, examples can be given of how HV suddenly appear, for example, in modern simulations of the angular distributions of gamma quanta or neutrons emitted from fission fragments. This happens if one considers the spin of each fragment to have a definite direction in the plane perpendicular to the fission axis, and then averages over the directions of the spin in the azimuthal plane. In this way, the well-known phenomenon of the alignment of the spins of fragments in a plane perpendicular to the fission axis might be erroneously treated. Then the supposed direction of the fragment’s spin appears as a HV. Contrary, in a consecutive quantum-mechanical approach, the state of the fragment is characterized by two quantum numbers: the spin and its projection onto the quantization axis z, which is along the fission axis. Then the alignment of the fragments merely means that the projection of their spins onto this axis is close to zero. And in the general case of incomplete alignment, it is necessary to use the density matrix.
A comparative analysis of experiments [1,2] on studying the (n, f), on one hand, and (n, n), on the other hand, angular correlations in fission is carried out, based on the model proposed by muonic conversion in fragments of prompt fission of 238U with negative muons. Their fundamental difference is shown in the sense of the information that can be inferred from them. To show this explicitly, and for the purpose of testing the experimental method, I propose an experimental check of the empirical relation between the alignment and polarization parameters, respectively:
AnJ = 2 Anf .
Among the other examples of use of HV, I point out the use of the immeasurable parameter ξ in the method of specific differences for the elimination of the Bohr—Weisskopf effect in the study of the hyperfine splitting in heavy ions of 209Bi [3].

1. A. Chietera, L. Stuttge, F. Gönnenwein et al. EPJ A 54, 98 (2018).
2. I.S. Guseva, in Proceedings of ISINN-23, Dubna, May 25-29, 2015, JINR, E3-2016-12 (Dubna, 2016), p. 80.
3. L. V. Skripnikov, S. Schmidt, J. Ullmann et al. Phys. Rev. Lett. 120, 093001 (2018).

Speaker: Feodor Karpeshin

HV2.docx

11:10 HYDROGEN ISOTOPES PRODUCTION UNDER (pi-)- MESON ABSORPTION IN SILICON “LIVE” TAGET

The results of the analysis of the outputs p, d, t formed under the absorption of stopped π-mesons by silicon nuclei are presented. The measurements were performed using a "live" target - Si detector (analog of the 28Si target). For the 28Si nucleus, the spectrum of primary protons was obtained from the absorption act on the pp pair when both particles (n and p) are not distorted by secondary interactions. It is shown that the data on proton yield do not contradict the assumption that the ratio of widths of elementary pion absorption processes on pn and pp pairs (R’ = 3.5) is constant. "Direct", without excitation, mechanisms of formation of deuterons and tritons on silicon were found, and their yields were estimated at a level ≥ 30%. This result makes it possible to test models of the formation of complex particles associated with the excitation of nuclei.

Speaker: Dr Boris Chernyshev (National Research Nuclear University “MEPhI)

97_ Gurov_2022.DOCX

Gurov_22.pdf

11:10 Is Electroweak Interaction – a Kind of Cosmological Lambda Term in Maintaining Nuclear Existence and Stability?

Considering the interaction scheme associated with Up quarks, Down quarks and pions and interaction scheme associated with electroweak bosons, we have developed a new model of nucleus. We would like to emphasize the point that atomic nucleus cannot exist without the support of electroweak interaction. Clearly speaking, analogous to the cosmological Lambda term, electroweak interaction helps in maintaining the existence of atomic nucleus without collapsing due to strong interaction. Interesting points to be noted are: 1) Up quark and Down quark play a vital role in understanding nuclear structure. 2) Mass ratio of pions and weak bosons is 0.0016 and it is approximately twice the product of Fine structure ratio and strong coupling constant. 3) Twice the proton number and the coefficient 0.0016 play a significant role in understanding nuclear stability line. 4) Currently believed harmonic oscillator coupling and spin-orbit coupling seem to be a natural manifestation of Up and Down quark arrangement. 5) Number range associated with harmonic oscillator coupling and spin-orbit coupling can be considered as a representation of mass number range of a proton number having magic behaviour. 6) Coefficient of proportionality being 0.0016, number of free nucleons increases with half the sum of squared number of protons and squared number of nucleons. 7) Increasing number of free nucleons, increasing nuclear radii and increasing asymmetry about stable mass number play an important role in reducing nuclear binding energy. 8) Nuclear binding energy can be addressed with four simple terms and single energy coefficient. 9) Unified nuclear binding energy coefficient is associated with the average rest energy of 3 Up quarks and 3 Down quarks. 10) Nuclear stability line, proton drip lines and neutron drip lines can be understood in a unified approach.

Speaker: Seshavatharam UVS (I-SERVE, Survey no-42, Hitech city, Hyderabad-84,Telangana, India)

ewines_uvssa_sln_24Jan2022.docx

ID_25_24_uvssa_sln_14July2022.pdf

ID6_Seshavatharam_Poster_Nucleus2022_12July2022.pdf

11:10 MODERNIZATION OF CORSET SETUP TO MEASURE CHARGE DISTRIBUTIONS OF FISSION FRAGMENTS USING BRAGG IONIZATION CHAMBER

Because fission is the result of competition between electrostatic and nuclear forces, information about the distribution of charge is critical to understanding the dynamics of a fissioning nucleus, as well as refining the parameters of fission process models needed for their developing. In this regard, the measurement of the charges of fission fragments is a crucially important task, therefore, various methods have been developed for measuring charges based on the Bethe-Bloch theory [1], which relates the specific energy loss to the charge number Z. One of these methods is the determination of the charge by the Brag peak [2], which is widely used both in nuclear physics experiments and applied research [3–7].
A system for measuring the charge distributions of fission fragments using an axial Bragg ionization chamber (BIC) has been developed. The design of the chamber makes it possible to change the distance between the cathode and the anode, which, in turn, along with a change in the pressure of the working gas, makes it possible to register a wider range of charge distributions depending on the task. The development of a technique for extracting information about the charge number from the signals of the BIC will significantly expand the range of tasks of the CORSET time-of-flight spectrometer [8]. In addition to measuring the mass-energy distributions, the charge distributions of fission fragments will be measured. The upgraded setup has the ability to smoothly change the angles of the Bragg ionization chamber, which allows one to measure the charge distributions of fragments emitted at different angles relative to the beam. This work presents test measurements.

1. H. Bethe und J. Ashkin in "Experimental Nuclear Physics, New York, 1953, p. 253
2. C.R. Gruhn, et al., Bragg curve spectroscopy, Nucl. Instrum. Meth. 196 (1982) 33-40
3. J.M. Asselineau, et al., Performance of a bragg curve detector for heavy ion identification, Nucl. Instrum. Methods 204 (1982) 109–115.
4. A. Oed, P. Geltenbort, F. Gönnenwein, A new method to identify nuclear charges of fission fragments, Nucl. Instrum. Methods 205 (1983) 451–453.
5. W. Neubert, Bragg curve spectroscopy of fission fragments by using parallel plate avalanche counters, Nucl. Instrum. Methods A 237 (1985) 535–542.
6. Kamanin, D.V., et al., Proc. Int. Symp. on Exotic Nuclei. EXON2004 (Peterhof, Russia, 2004), Singapore: World Sci., 2005, p. 588.
7. E. Pellereau, et al., Accurate isotopic fission yields of electromagnetically-induced fission of 238U measured in inverse kinematics at relativistic energies, Phys. Rev. C 95 (2017) 054603
8. Kozulin, E.M., et al., Instrum. Exp. Tech., 2008, vol. 51, p. 44.

Speakers: Dr Vahan Kirakosyan (Joint Institute for Nuclear Research) , Dr Yerzhan Mukhamejanov (Joint Institute for Nuclear Research) , Mr Artem Ostroukhov (Joint Institute for Nuclear Research)

nucleus-2022-abstract-modernization of corset setup_bragg.docx

11:10 New approaches to neutron monitoring in low background neutrino experiments

In this work the new methods for neutron detection in low background experiments are presented.
During study of background conditions of νGeN and Ricochet neutrino experiments is has been shown that low intrinsic background helium-3 filled tubes are suitable not only for well known detection of thermal neutrons, but also for the fast neutrons with energies up to few MeV.
Alternative to the helium-3 could be NaI (Li+Tl) detectors. One such of the detectors loaded with 1% of natural lithium was experimentally studied. The MC calculations based on our data shows that in a case of the detector loaded with 2% of lithium-6 and with its background reduced to the lowest values of available NaI detectors, it will becomes possible simultaneous measurement of low level fluxes for thermal, epithermal and fast neutrons. That possibility, together with traditional γ– measurements, looks very promising for background characterization at neutrino experiment sites.

Speaker: Dmitrii Ponomarev (JINR)

New approaches to neutron monitoring in low background neutrino experiments.docx

11:10 ON THE WIDTH OF γ-LINE AND THE PHOTON STRUCTURE

The reason to turn once again to the question of the natural width Гγ of the
γ-radiation line of nuclei is provided by the discovery of an increase in the half-life T1/2 for nuclear isomers in a metal matrix (see ref. [1] and references therein). For nuclei in such a matrix, a decrease in the width Гγ can be expected, since, according to generally accepted concepts, Гγ   / T1/2 for the emission of photons in a nuclear transition from an excited state E of a half-life T1/2 to the ground state.
However, even in early Mössbauer experiments with the 57mFe isomer, a decrease in Гγ was observed with an increase in the age of the E level (see, e.g., ref. [2]), which could be interpreted as a result of a decrease in the level width with its age. But such an interpretation is not allowed by the experiment [3] with the 181mTa isomer (T1/2 ≈ 6 µs), in which broadening of the 6.2 keV γ-line was observed due only to the shading of the absorber from the emitter by a mechanical chopper, which opened their mutual visibility for a time of 1 µs without referencing by the time the isomer was formed. Hence it follows that the width Гγ is determined not by the value of T1/2, but only by the time Tγ, which in the Mössbaur experiments the absorber nucleus sees the emitter before the emission of an energy quantum. Of course, if there are no restrictions on the measurement time of the width Гγ, then the average value Tγ is proportional to T1/2.
Then, taking into account that the energy of the γ-transition is emitted in less than 1 ns – this can be seen, for example, from the duration of the γ-signal in the scintillator, we can assume the following photon structure. Immediately after the formation of the excited state E, the nucleus begins to emit an electromagnetic wave of frequency ω that does not carry energy – abbreviated as a 0-wave. The duration of this 0-wave determines the width Гγ. The energy quantum ω is emitted at the end of the 0-wave. The energy ω may not be emitted at all if the state E decays via another channel, and then the 0-wave will exist on its own, without an energy quantum. A possible source of the 0-wave is the virtual transitions from the E* level to the ground state and back before the emission of an energy quantum.
The 0-wave with a quantum ω “on its tail” resembles a pilot wave introduced by De Broglie to explain the wave-particle duality of electrons. It is interesting to study effect of 0-waves on absorber nuclei, for example, to search for the modulation of the Гγ value via an additional resonance irradiation of the absorber in Mössbaur experiments.

1. V.V. Koltsov, Bull. Russ. Acad. Sci.: Phys. 83, 1144 (2019).
2. W. Triftshauser, P.P. Craig, Phys. Rev. Lett. 16, 1161 (1966).
3. V.K. Voitovetsky, I.L. Korsunsky, Yu.F. Pazhin et al., Yad. Fiz. 38, 662 (1983).

Speaker: Vladimir Koltsov (Khlopin Radium Institute, Saint-Petersburg, Russian Federation)

Abstracts Koltsov Nucleus 2022 .docx

Koltsov - ON THE WIDTH OF γ-LINE .pdf

11:10 Preliminary data of the experiment to determine the cluster structure of the excited states of the 6Li

A test experiment to determine the cluster structure of the excited states of the 6Li nucleus in the n + 6Li reaction with registration of charged particles and neutrons in coincidence was carried out on the RADEX neutron channel of INR RAS. Charged particles were registered by a telescope of silicon ∆E-E detectors at an angle of 50º in a small vacuum scattering chamber with a mounted 6Li2CO3 target [1]. Neutrons were registered by three scintillation detectors at an angle of 80º on the other side of the beam axis. Preliminary data on the energy spectra of neutrons and charged particles have been obtained. The obtained data make it possible to estimate the beam time required to obtain statistically reliable data for studying the cluster structure of highly excited states of the 6Li nucleus.

1. A. Kasparov, M. Mordovskoy, V. Mitcuk, A. Afonin // “Nucleus-2021”, Book of Abstracts, 89 (2021).

Speaker: Michael Mordovskoy (INR RAS)

nLi6.doc

11:10 SIMPLE METHOD FOR OBTAINING MASS DISTRIBUTIONS OF FISSION FRAGMENTS

An experimental method is presented for simply obtaining the mass distributions of fission fragments.
A feature of this method is the simultaneous use of two detectors for time-of-flight measurements, one of which is considered as a start detector and the other as a stop detector. The relevant quantity in the described method is the difference in the time of flight of two coinciding fission fragments ᐃT (used earlier, for example, in Refs [1,2]).
It is shown, that the distribution form ᐃT obtained for two additional fragments is completely identical to their mass distribution.
The paper presents the time-of-flight difference spectra of fragments of spontaneous fission {252}^Cf and induced fission of target nuclei {238}^U and {nat}^W, measured by detectors located on both sides of the target.
Experiments on U and W fission were carried out on a proton beam with an energy of E_{p} = 1 GeV at the PNPI synchrocyclotron.

1. G. G. Semenchuk, et al., Preprint of LNPI. 171, (1975).
2. C. Guet, M. Asghar, P. Perrin, and C. Signarbieux, NIM. 150, 189 (1978).

Speaker: Lyudmila Andronenko (Petersburg Nuclear Physics Institute of NRC KI - Address: 188300, Gatchina, Orlova Roshya 1)

Andronenko_nucleus-2022-abstract.docx

11:10 SOME REGULARITIES IN THE FORWARD ANGLE YIELDS OF ISOTOPES WITH 4<Z<20 IN THE REACTION OF 40AR(40 A MEV) WITH 9BE.

Systematic study of forward-angle inclusive yields of nuclei with atomic numbers 4<Z<20 produced in nucleus-nucleus collisions of the 40Ar projectile on the 9Be target in the Fermi energy domain (40 A MeV) was carried out. The reaction products were measured by using the double achromatic fragment-separator COMBAS [1, 2] in the spectrometry mode at FLNR, JINR (Dubna). The inclusive velocity, isotopic and element distributions were obtained. There is no unique mechanism to explain the total set of the results obtained from the experiment. Two main contributions of dissipative low energy reaction mechanisms and of fragmentation mode were observed. The simple exponential approximation realized by the Qgg – systematics satisfactorily describes the total yield of the isotopes produced in stripping nucleon reactions with large negative Qgg values especially for neutron-rich isotopes. The Qgg – systematic can be used to predict correctly the yields of unknown drip-line nuclei. The production rates of neutron-rich isotopes of elements with 4 < Z < 20 were determined.

1. A. G. Artukh, A. N. Vorontsov, S. A. Klygin, G. A. Kononenko, Yu. M. Sereda, B.Erdemchimeg, Physics of Particles and Nuclei Letters, 2021, Vol. 18, pp. 19–26
2. A. G. Artukh, Yu.M. Sereda, S. A. Klygin and et al, Instruments and Experimental Technique, 2011, Vol. 54, № 5, pp. 668-681

Speaker: Erdemchimeg Batchuluun (FLNR, JINR)

erdem nucleus2022_a.pdf

Some regularities in the beam2.doc

11:10 STUDY EXCITATION OF ISOMERIC STATES IN $(\gamma,n)$, $(n,2n)$ AND $(n,\gamma)$ REACTIONS ON $^{108,110} Pd$

This work presents work results of investigation of the isomeric yield ratios of the $^{110} Pd (\gamma,n)^{109m,g} Pd$, $^{110} Pd (n,2n) ^{109m,g} Pd$ and $^{108} Pd (n,\gamma) ^{109m,g} Pd$ reactions. The isomeric yield ratios were measured by the induced radioactivity method. Samples of natural Pd (Palladium metal foils) have been irradiated in the bremsstrahlung beam in the energy range of $10\div 35$ MeV with energy step of $1$ MeV. For $14$ MeV neutron irradiation, we used the NG-150 neutron generator. For the $(n, \gamma)$ reaction, experiments were carried out at the ВВЗ-СМ research reactor of the Institute of Nuclear Physics of the Academy of Sciences of the Republic of Uzbekistan.

The gamma spectra reactions products were measured with a spectroscopic system consisting of HPGe detector CANBERRA with energy resolution of $1.8$ keV at $1332$ keV gamma ray of $^{60} Co$, amplifier 2022 and multichannel analyzer 8192 connected to computer for data processing. The filling of the isomeric and ground levels was identified according to their $\gamma$ lines. The values of isomeric ratios for the reactions $(\gamma, n)$, $(n, 2n)$ and $(n, \gamma)$ are respectively: $0.063 \pm 0.003$ (at $E_{\gamma max} = 30$ MeV); $0.43 \pm 0.03$ (at $E_n=14.1$ MeV) and $9.1 \pm 0.8$. Using the isomer yield ratio and the total cross section of the $(\gamma, n)$ reaction on $^{110} Pd$ [1] received the cross sections of $(\gamma, n) ^m $ and $(\gamma, n) ^g $ reactions. The cross section isomeric ratios at $E_{\gamma}=E_m$ are estimated.

The isomeric cross-section ratios were determined in the case of the reaction $(n, 2n)$. In order to obtain the absolute values of the cross sections for the ground state and fot the isomeric state, use was made of methods based on comparing the yields of the reaction under study and the monitoring reaction. The reaction $^{27} Al (n,\alpha) ^{24} Na$ ($T_{1/2} = 15$ h, $E_{\gamma} = 1368$ keV). For reaction $(n, \gamma)$, $^{197} Au (n, \gamma)$ was used as a monitor reaction.

The experimental results have been discussed, compared with those of other authors as well as considered by the statistical model. Theoretical values of the isomeric yield ratios have been calculated by using code TALYS-1.6.

1. A.V. Varlamov et al. Atlas of GDR. INDS(NDS)-394.// Vienna: IAEA, 1999.

Speaker: Prof. Satimboy Palvanov (National University of Uzbekistan)

Palvanov S.R. Pd2.docx

11:10 STUDY OF THE EXCITATION OF ISOMERIC STATES IN $(\gamma, n)$, $(n, 2n)$ AND $(n, \gamma)$ REACTIONS ON $^{198,200}Hg$ NUCLEI

The isomeric ratios in reactions of the $(\gamma, n)$, $(n, 2n)$ and $(n, \gamma)$ types on $^{180,200}Hg$ nuclei in the energy range of $10-35$ MeV have been studied by the method of induced activity. Samples of mercury oxide (HgO) have been irradiated in the bremsstrahlung beam of the betatron of the National University of Uzbekistan in the energy range of $10 \pm 35$ MeV with an energy step of $1$ MeV. For $14$ MeV neutron irradiation we used the NG-150 [1] neutron generator of the Institute of Nuclear Physics. For the $(n, \gamma)$ reaction, experiments were carried out at the ВВЗ-СM research reactor of the Institute of Nuclear Physics of the Academy of Sciences of the Republic of Uzbekistan.

The induced $\gamma$-activity of the targets was measured on a Canberra $\gamma$ -ray spectrometer, consisting of an HPGe germanium detector (with a relative efficiency of 15%, a resolution for the $^{60}Co$ $1332$ keV line - $1.8$ keV), a DSA 1000 digital analyzer, and a personal computer with the Genie software package.

The experimental results have been discussed, compared with those of other authors as well as considered by the statistical model. Theoretical values of the isomeric yield ratios have been calculated by using code TALYS-1.6 [2].

1. http://www.inp.uz
2. A.J. Koning, J.P. Delaroche. Nucl. Phys. A 713 (2003) 231.

Speaker: Prof. Satimboy Palvanov (National University of Uzbekistan)

Palvanov S.R. Hg.docx

11:10 Test experiment to determine the time distribution of the background between MMF accelerator pulses on the RADEX channel.

To determine the possibility of studying various cluster structures (for example, [1]) in light nuclei on the RADEX neutron channel of the MMF INR RAS accelerator, it is necessary to carry out a study to measure the background between accelerator pulses (the level, composition and time distribution of it). For example, when searching for the cluster structure of α-4n-α and 8Be-4n in the highly-excited state of 12Be, it is necessary to detect charged particles from the b-decay of 12Be during its formation in the n + 13C reaction in the intervals between pulses of cascade neutrons [2]. This will be possible with a certain background level and its time distribution.
The first experiments of this kind were carried out on the RADEX MMF channel at several pulse durations and frequencies from 1 to 50 Hz. Between the pulses of the accelerator, the spectra and time distribution of gamma quanta, neutrons, and b-particles were measured. The first measurement results are presented.

1. Marque's F.M. , et al. // Phys.Rev. C. 65, 044006 (2002).
2. A. Kasparov, M. Mordovskoy, V. Skorkin // “Nucleus-2021”, Book of Abstracts, 317
   (2021).

Speaker: Michael Mordovskoy (INR RAS)

After_pulse_background.doc

11:10 USING A ΔE(SI)-E(CSI(TL)) TELESCOPE TO IDENTIFY LIGHT CHARGED PARTICLES

In this work the analog, digital and combination (analog-digital) electronic readout methods of pulse analysis of ΔE-E telescope detectors were studied. The ΔE-E telescope, consisting of thin Si-detector (H = 100 um) as a ΔE detector and CsI(Tl) scintillator (H = 20 mm) activated with Tl 0.7% as an E detector was used. The analog method of pulse analysis was carried out by using a dual spectroscopic amplifier Ortec-855 at the different integration times (τ = 0.5÷3.0 us) and a VME module of the analog-to-digital converter Mesytec MADC-32. The digital method of pulse analysis was carried out using a pulse processor Mesytec MDPP-16 CsI.
In the report the electronic block schemes and two dimensional ΔE×E spectra obtained by the above mentioned methods were presented. The main attention was focused on the dynamic range of the detected particle identification.
The 1,2,3H, 4He light charged particles with high positive Qgg value of the 6Li+9Be reaction together with 6,7Li isotopes were registered by ΔE×E telescope at the broad energy range. It was shown that the combined and digital electronic readout methods of pulse analysis give the most effective particle identification at low-energy and high-energy ranges, respectively.
The measurements were carried out with 6Li beam at E = 10 MeV/nucleon of the U400 cyclotron at the FLNR JINR.

Speaker: Mr Zhassulan Zeinulla (JINR, Dubna, Russia)

Nucleus-2022_ZeinullaZh_thesis4poster.doc

10:00 → 11:30 Poster session: Intermediate and high energies, heavy ion collisions

10:00 QUARK-GLUON STRING MODEL (QGSM) AND ITS APPLICATION FOR INELASTIC DC INTERACTIONS AT A MOMENTUM OF 4.2 A GEV/S

QUARK-GLUON STRING MODEL (QGSM) AND ITS APPLICATION FOR INELASTIC DC INTERACTIONS AT A MOMENTUM OF 4.2 A GEV/S

R. Bekmirzaev1, M.U.Sultanov2, S. Yuldashev3

1State Pedagogical Institutes, 130100, Jizzakh, Uzbekistan
bekmirzaev@mail.ru
2State Architecture and Civil Engineering Institute, Samarkand, Uzbekistan
3Samarkand State University, Samarkand, Uzbekistan

The construction of high-energy accelerators for hadrons and the creation of detectors that record reaction products are very costly. At the same time, there is a need to compare the experimental conditions and large-scale experimental data with the results of theoretical calculations. As a result, a large number of software generators for the collisions of hadrons and nuclei of different energies have emerged. These programs are based on a standard model (various phenomenological models) of strong and non-electric interactions. Of these, ISAJET and Lund University programs, including PYTHIA and FRITIOF, are popular. These programs open up almost all areas of transmitted momentum (P2, quarks and from strong scattering of gluons to the formation and decay of hadrons). In this work, the main provisions of the Quark-gluon string model for describing inelastic interactions of light nuclei at high energies are presented. The main ideas of the CGSM model are given, such as the process of formation of quark-gluon strings and the choice of their limited number, modeling of string breaking with the formation of hadrons [1]. The data of theoretical calculations by CGSM are compared with the experimental results obtained for dC-inelastic interactions. The technique for obtaining experimental data is briefly described. Analysis and comparison of model and experimental information shows that the CGSM model reproduces well the interactions of light colliding nuclei at energies of 4.2 GeV/s, and it is applicable up to the energy of nuclear interactions of 10 GeV/nucleon [2-3]. Low experimental data on 4π geometry were obtained. Therefore, it is important to study the formation of cumulative particles in large experimental statistics.
Reference
1. Feynman R.P., Field R.D. Nucl.Phys. V.B136, (1978). p.1.
2. Olimov, K. et al. Reports of Uzbek Academy of Sciences 29, 4 , (2011)
3. Olimov, K. et al., International Journal of Modern Physics E, 29, 4 (2020).

Speaker: raxmatillo bekmirzaev (nurmurodovich)

nucleus-2022-abstract_bekmirzaev-sultanov.docx

10:20 TRANSVERSE MOMENTUM FLUCTUATIONS IN NICA AND SPS ENERGY RANGE

Correlations between multiplicity of charge particles and mean transverse momentum were observed experimentally in p+p collisions from top SPS energy to LHC energy. The change in the correlation function’s shape with collision energy was successfully described by the multi-pomeron exchange model as an interplay of string fusion and energy-momentum conservation [1]. Previously, it was shown that phenomenological resonance-to-strings transition leads to rapid changes in the magnitude of pt-n correlations at the NICA energy range [2]. The mean transverse momentum is sensitive to the initial energy density [3] and, therefore, its event-by-event fluctuations are strongly affected by the event (centrality) selection. In this contribution results of the pt-n correlations analysis [2] would be extended by Monte-Carlo simulations studies for the pt-n strongly intensive observables [4], pt cumulants [5] and two-particle pt correlation measures [6]. That would allow testing the influence of the resonance-to-string transition and the role of conservation laws of the given observables.

1. N. Armesto, D. A, Derkach, and G. A. Feofilov, Phys. Atom. Nucl. 71, 2087 (2008).
2. A. Zvyagina, E. Andronov, Phys. Part. Nucl. 53(2), 117 (2022).
3. E. V. Shuryak, Phys. Lett. B 423, 9 (1998).
4. M. Gorenstein, M. Gazdzicki, Phys. Rev. C 84, 014904 (2011).
5. S. Bhatta, C. Zhang, and J. Jia, Phys. Rev. C 105 (2), 024904 (2022).
6. M. Cody et al., arXiv:2110.04884 [nucl-th].

Speaker: Dr A. P. Zviagina

nucleus-2022-abstract-zviagina_andronov.docx

10:40 COMPARISON OF SOME KINEMATICAL CHARACTERISTICS OF PROTONS IN COLLISIONS n12C AND p12C AT 4.2 GeV/s

COMPARISON OF SOME KINEMATICAL CHARACTERISTICS OF PROTONS IN COLLISIONS n12C AND p12C AT 4.2 GeV/s
R.N. Bekmirzaev 1 , Kh.K. Olimov 2
1 Jizzakh State Pedagogical Institute, 130100, Jizzakh, Uzbekistan,
bekmirzaev@mail.ru
2 Physical-Technical Institute of the Academy of Sciences of the Republic of Uzbekistan, 100084, Tashkent, Uzbekistan,
olimov@uzsci.net
It is known, the interaction of high-energy protons with nucleons and nuclei has been well studied experimentally in a wide range of primary energies, and due to the difficulties in obtaining monochromatic beams of neutral particles, experimental information on collisions of neutrons with nuclei (nA) obtained under the conditions of 4π-geometry very rare [1-3] and based on few statistics. Therefore, obtaining experimental data on nA collisions and comparing them with data on pA interactions at the same energy and for the same target nucleus is of considerable interest. The work is devoted to a comparative analysis of various kinematic characteristics of protons in n12C and p12C collisions at a momentum of 4.2 GeV/s.
Experimental material was obtained using a two-meter propane bubble chamber of the High Energy Laboratory of the Joint Institute for Nuclear Research (Dubna, Russia), irradiated with beams of protons, deuteron nuclei (d = 2H) and helium-4 at a momentum of 4.2 GeV/s per nucleon at the synchrophasotron in Dubna [2]. The average values of the total and transverse momenta of protons with their average escape angles and speed in n12C and p12C collisions are obtained separately for events with and without negative pions in the final state of the reaction. The average value of the total momentum of protons produced in n12C collisions with n (π−) = 0 is much smaller than in p12C collisions , since most of the protons in this case come from the target. In the case when one or several negative pions are formed in an event, the average value of the total momentum of protons in n12C collisions is greater than in p12C interactions .
A comparative analysis of the mean values of various kinematic characteristics of protons produced in n12C and p12C collisions at 4.2 GeV/s has been carried out. The difference in the average momenta of protons in n12C and p1 C is related to the difference in the probabilities of proton conservation in the first case and recharging of the primary neutron by a proton in the second.
REFERENCES
1. R. N. Bekmirzaev, Nuclear Physics, 40, 1477 (1984).
2. Olimov K et al., Reports of the Academy of Sciences of the Republic of Uzbekistan, 4 (2011) 29.
3. Olimov, K. et al., “Comparative analysis of characteristics of protons produced in n12C and p12C collisions at 4.2 GeV/s”, submitted to Intern. J. Mod. Phys. E, (2020).

Speaker: raxmatillo bekmirzaev (nurmurodovich)

nucleus 2022- bekmirzaev.doc

10:40 Confinement potential from holographic approach to strong interactions

We derive and analyze the confinement potential of the Cornell type between two static color sources within the framework of a generalized Soft Wall holographic approach to strong interactions. This approach was originally developed for describing the linear Regge spectrum of light mesons. The ''linear plus Coulomb'' confinement potential is obtained both in the vector and in scalar channels. It is shown that the quantitative agreement with the phenomenology and lattice simulations is better in the scalar channel.

Speaker: Sergey Afonin (Saint-Petersburg State University)

Afonin-abstract.docx

10:40 The Regge meson spectrum from holographic Wilson confinement criterion

Using the Wilson confinement criterion, a holographic model for finding a string-like spectrum of meson excitations is proposed. The model is applied to the vector and scalar mesons and a good agreement is obtained both with the existing experimental data and with some other known phenomenological approaches. The constructed model provides a novel realization of spontaneous chiral symmetry breaking between parity partners.

Speaker: Timofey Solomko (Saint-Petersburg State University)

Solomko-Abstract.docx

Solomko_poster.pdf

10:40 Ultra lightweight support structures and gaseous cooling system for the novel silicon pixel detectors

New research tasks in high-energy physics experiments require using the advanced materials and methods for the precise tracking and decay vertices registration of short-lived charged particles.
Therefore, very thin large area, coordinate-sensitive Si detectors with high granularity and the highest radiation transparency will be used for the innermost tracking layers on the next stage of the ALICE experiment at the LHC. Such vertex detectors can provide minimal distortions of the registered tracks because of the multiple scattering effects and their application is also being planned for NICA experiments at JINR. In present work, the conceptual ideas and results of developments of ultra lightweight support structures and cold nitrogen cooling system proposed for next-generation of radiation transparent vertex detectors are discussed [1].
Therefore, the lightweight and radiation transparent materials should be used to develop support structures and cooling system for new silicon pixel detectors. On the one hand, an ultra lightweight system has to be strong enough to support the detectors, on the other hand this system should be radiation transparent with the minimum material budget of its components. This means that all parts of the detector system, sensors, micro cables, support structures and cooling system should have a minimum amount of low-Z materials. The gaseous cooling of detectors is being considered as an appropriate option [2]. In this case, we need to avoid vibrations, that could happen for very thin (~ 20 micron), large area Si detectors in case of the non-negligible speed required for the gas flow. In order to reduce these micro-vibrations the low-speed flow of the cold gas was proposed.
In present work, our developments of ultra lightweight, support structures with cold nitrogen cooling system for new generation of thin, large area, coordinate-sensitive Si detectors are presented.
This work is supported by the SPbSU grant ID: 93025208
Referencies:
1. First demonstration of in-beam performance of bent Monolithic Active Pixel Sensors, ALICE ITS project Collaboration, G. Aglieri Rinella (CERN) et al, Nucl.Instrum.Meth.A 1028 (2022)
2. Physics Briefing Book : Input for the European Strategy for Particle Physics Update 2020, Ellis, Richard Keith (Durham U., IPPP) et al. CERN, Report number: CERN-ESU-004 (See p.212, contribution 46: G. Feofilov et al., “Heavy-flavour production in relativistic heavy-ion collisions and development of novel generation of extra- low-material-budget Vertex Detectors for future experiments at CERN and JINR”).

Speaker: Vera Misheneva

Thesis.docx

10:00 → 11:30 Poster session: Neutrino physics and nuclear astrophysics

10:00 Precision measurements of 210Bi β-spectrum for neutrino physics tasks.

The isotope 210Bi is an element of 238U natural decay chain. As decay product of 222Rn gas and subsequent long-lived 210Pb, the 210Bi isotope is present inside and on the surface of all structural materials. At present, accurate measurement of 210Bi β-spectrum is necessary for background simulation of modern neutrino and dark matter detectors, as well as for other low-background experiments. In particular, the shape of 210Bi β-spectrum is very similar to the spectrum of recoil electrons from the scattering of solar CNO-neutrinos.
The β-spectrum was measured with two types of Si-spectrometers developed and manufactured at the PNPI. To register electrons in a spectrometer designed according to the classical "target-detector" scheme, a Si(Li) detector 15 mm in diameter and 7 mm thick was used [1]. The main difference of the new 4πβ- spectrometer is the response function, which is close to Gaussian, which does not require careful consideration of electron backscattering from the crystal surface [2,3]. As a result of two independent measurements, the values of the nuclear form factor parameters are determined with an accuracy better than a percent and are consistent with each other.

1. Alekseev I.E., Bakhlanov S.V., Derbin A.V., Drachnev I.S., Kotina I.M., Lomskaya I.S., Muratova V.N., Niyazova N.V., Semenov D.A., Trushin M.V., Unzhakov E.V., Phys. Rev. C 102, 064329 (2020).
   2 Alekseev I.E., Bakhlanov S.V., Derbin A.V., Drachnev I.S., Kotina I.M., Lomskaya I.S., Muratova V.N., Niyazova N.V., Semenov D.A., Trushin M.V., Unzhakov E.V. J. Phys.: Conf. Ser. 2103, 012144 (2021).
2. Bakhlanov S.V., Derbin A.V., Drachnev I.S., Kotina I.M., Lomskaya I.S., Muratova V.N., Niyazova N.V., Semenov D.A., Trushin M.V., Unzhakov E.V., Chmell E.A. Instrum. Exp. Tech., 64, 190 (2021).

Speaker: Alexander Derbin (Petersburg Nuclear Physics Institute NRC KI)

Nucleus2022_Derbin_210Bi_A1_poster.pdf

10:40 Precision measurement of 144Ce – 144Pr beta-spectrum

Beta-decay is a specific decay process that undergoes a reaction with thee-particle product composition that results in continuous spectral shape of electrons or positrons. The shape of the spectrum was described already in 1934 by E. Fermi [1], but such description appeared to be valid only for allowed transitions (ΔI = 0,1 Δπ = 1). Involvement of nuclear exchange in other types of transitions complicates such decay description and often makes it necessary to perform experimental evaluation.
Precision beta-spectra measurement always had a great importance in some fundamental physics problems including neutrino physics, e.g. a 144Ce – 144Pr source is one of the most suitable to search for neutrino oscillation into sterile state for sterile neutrino mass around 1 eV. Magnetic and electrostatic spectrometers have high resolution, but at the same time usage of such kinds of equipment involves the size and cost issues. Since electron mean free path at the energy of 3 MeV (which is basically the maximum energy of a beta-transition for the long-lived nuclei) does not exceed 2 g/cm2, electron registration could be effectively performed with the solid state scintillators and semiconductors.
A strong probability of backscattering from detector surface is present in case of semiconductor detectors and is dependent upon the detector material. One possible way of solving this issue is a precise simulation of the spectrometer response function that is quite promising as it could be used in a very simple target-detector setup. Another solution to this problem is usage of 4π geometry [2], that fully covers the radioactive source and is able to register the backscattered electrons.
In this work we present the results of 144Ce – 144Pr spectrum measurement performed with two setups of both types and controlled with the shape of an allowed 0- – 1- transition in 144Pr, having precision that was substantially increased with respect to the previous studies of these beta-spectra. We have obtained parameter values for the paramertrized transition shape factor that is compared with the other experiments and could be used for electron antineutrino spectrum definition.

Speaker: Ilia Drachnev (PNPI NRC KI)

abstract_drachnev_144Ce-144Pr.docx

Nucleus_2022_Drachnev_144Ce_A1_poster.pdf

11:00 LOW RADIOACTIVE AMMONIUM ACETATE FLUX

LOW RADIOACTIVE AMMONIUM ACETATE FLUX

N.A. Mirzayev a,b*, Kh. Mammadov b, D.V. Karaivanov a,c, N. Temerbulatova a, A. Rakhimov a, S. Rozov a E. Yakushev a , D. Filosofov a

aLaboratory of Nuclear Problems, JINR, Dubna, 141980, Russia
bInstitute of Radiation Problems of Azerbaijan National Academy of Sciences, Baku, Azerbaijan
cInstitute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria

E-mail: mirzayev@jinr.ru.

The background event is a critical indicator, in all low background experiments. With the rate of signal events of detector, it is crucial to minimize the presence of radioactive isotopes. Solder and flux is one of the essential materials for making reliable electrical connections in sensitive parts of the experiment. Literature dates report a problem with unacceptable radioactive contamination of commercially available fluxes.
In this work we continued to analyze the low-background flux problem and to produce CH3COONH4 organic flux from pre-purified materials. The main application of the flux is for EDELWEISS and CUPID-Mo experiments, which use bolometric technique in LSM underground laboratory for direct Dark Matter detection and for 0ν2β search, respectively. An instrumental neutron activation analysis (INAA), Inductively Coupled Plasma Emission Spectrometry (ICP-AES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) have been performed to estimate the radioactivity level and impurity content of the products. Additionally, the composition of a high purity commercial ammonium acetate flux (CH3COONH4 OSCh 5-4) was analyzed by the same methods to assess the purity of the « custom–made » ammonium flux. The concentration of all impurities in commercial ammonium flux is more significant than custom-made analog. These dates report the advantage of synthesis method of custom-made flux.

Speakers: Nijat Mirzayev, Khaqani Mammadov , Midko Karaivanov , Nargiza Temerbulatova , Alimardon Rakhimov, Sergey Rozov, Evgeniy Yakushev, Dmitry Filosofov

nucleus-2022- mirzayev.docx

11:10 A NEW OUTLOOK ON THE SQUARE-WELL POTENTIAL APPROACH FOR ASTROPHYSICAL FUSION REACTION

Latest achievements in experimental study of light nuclei fusion reactions relevant for nuclear astrophysics in the deep subbarrier region required the development of models that make it possible to describe the reaction cross section at low energies [1]. Today there is no unified approach to describe such reactions: a) with excluding of the potential choice ambiguity [2]; b) with the description of the resonant nature of the cross section [3] and its hindrance for low energies [1].
As a first approach we can consider the square-well potential, which allows a simple analytical expression to determine the transmission coefficients and hence the reaction cross section. As was shown in [4], this model gives us the possibility to describe the fusion cross section in the low-energy region for 16O + 16O nuclei with sufficient accuracy.
In present work, the square-well model was applied to the light nuclei (10B, 12C, 14N, 16O, 18O, 20Ne) fusion reactions important for nuclear astrophysics. Functional dependences for the potential depth and well’s radius were obtained. Artifacts associated with abruptly changed shallow potential well: overestimations of the channel radius, anomalous behavior of the imaginary potential for a number of reactions were determined.
It was shown that, within the framework of used model, a satisfactory description can be achieved for all investigated reactions.

1. C. L. Jiang, B. B. Back, K. E. Rehm et al, Eur. Phys. J. A 57, 235 (2021).
2. S. Y. Torilov, N. A. Maltsev and V. I. Zherebchevsky, Bull. Russ. Acad. Sci. Phys. 85, 548 (2021).
3. S. Y. Torilov, N. A. Maltsev and V. I. Zherebchevsky et al, Phys. Part. Nuclei 53, 403 (2022)
4. R. Ogura, K. Hagino and C. A. Bertulani, Phys. Phys. Rev. C 99, 065808 (2019).

Speaker: Sergey Torilov (St. Petersburg State University)

nucleus-2022-abstract-Torilov.docx

poster.pdf

11:10 DETERMINATION OF THE ENERGY OF HIGH-ENERGY PROTONS (1 TEV AND HIGHER) BY THE LFM METHOD

Calorimetric methods are currently practically the only way to directly measure the characteristics of high energy (TeV and higher) cosmic nuclei. The primary particle, interacting with the substance of the calorimeter, gives rise to a cascade of secondary particles in it. To measure the characteristics of the cascade, the dense matter is interbedded with special detectors. Based on the measurements of signals from these detectors, a cascade curve is formed. If the cascade curve has reached a maximum in the calorimeter, then the primary energy is reconstructed quite accurately. However, to measure the maximum of the cascade, the calorimeter must have a sufficiently large thickness (and so large weight). When using thin calorimeters, the primary energy is determined with a large error (30-70 percent when measuring hadronic cascades) due to significant fluctuations in the development of the cascade curve. In this regard, the energy spectrum of cosmic rays for energies of 1-100 TeV is currently poorly understood, since different experimental groups present different spectra of cosmic rays.
In this paper, to solve this problem, it is proposed to use the Lessening Fluctuation Method (LFM) based on correlation curves. In this method, instead of cascade curves, correlation curves of the dependence of the cascade size on the rate of cascade development are used. The cascade development rate is understood as a quantity equal to the difference in the cascade sizes at two measurement levels, divided by the thickness of the calorimeter, during the passage of which this change in the cascade size occurred. The rate of cascade development depends on the primary energy and therefore it can be used as an additional quantity to improve the accuracy of primary energy reconstruction. The correlation curves almost do not fluctuate and make it possible to determine the energy of cascades that have not reached a maximum. To test the LFM, we simulated the passage of cascades formed by protons with energies of 1-10 TeV through the PAMELA collaboration calorimeter. Based on the simulation, it was shown that the correlation curves almost do not fluctuate. This makes it possible to significantly reduce measurement errors (up to ~10 percent when measuring hadron cascades). Moreover, LFMs make it possible to correctly determine the energy of cascades that have not reached their maximum. This makes it possible to solve the problem of the large weight of the calorimeter.
The study was financially supported by the Ministry of Education and Science of the Republic of Kazakhstan (grant no. AP08855403).

Speaker: Anastasiya Fedosimova

nucleus-2022-abstrac-питер калориметр (1).docx

11:10 iDREAM detector today

The industrial idream detector was installed at Unit 3 of Kalinin NPP in spring 2021. Data collection had been going on since last spring and after 4-month break since last november, we has continued data collection this spring, evaluated liquid scintillator stability, background conditions, and would like tell about the first plans to upgrade the detector in the future

Speaker: andrei konstantinov

nucleus-2022-abstract iDREAM today.docx

poster nucleas-2022 konstantinov.jpg

poster nucleas-2022 konstantinov.pdf

11:10 Radio detection of neutrinos in Antarctica

The radio detection of UHE neutrinos is currently being actively developed. Radio experiments carried out in Antarctica (ARIANNA, ARA, ANITA balloon experiment) are able to scan huge volumes of ice in search of neutrinos.
The scale of the experiments is growing - work is underway to deploy an array of radio detectors in the Greenland Ice Sheet, it is planned to build a new radio detector at the South Pole (IceCube Gen-2 radio) and launch a balloon experiment PUEO.
The detection method is based on the Askaryan effect predicted by a Soviet physicist in 1962. Due to this effect, UHE neutrino-induced cascades in ice radiates in the radio range. And the radio transparency of polar ice makes it possible to cover large volumes of the target with sparse array of radio antennas.
In this work, the abilities of AURA experiment to detect UHE neutrino were explored.
The AURA is a pilot radio experiment whose antennas are deployed in IceCube holes in polar ice at a depth of 200-1500 m. The experiment was carried out from 2006 to 2011 to study the background conditions at the South Pole. Its distinguishing feature is the presence of deeply located antennas.
In the work it is shown which radio noise sources are present at the South Pole and how they affect on the efficiency of neutrino detection. The relationship between settings of the trigger system and the thermal noise level recorded by the equipment has been studied. And the possibilities of the AURA experiment for detecting UHE neutrinos are presented here.

Speaker: Maria Mikhailova

nucleus-2022-abstract-mmv.docx

10:00 → 11:30 Poster session: Nuclear structure: theory and experiment

10:00 STRUCTURE AND SYNTHESIS OF MAGNETIZED HEAVY NUCLEI

Nucleosynthesis at large magnetic induction relevant for core-collapse supernovae, and neutron star mergers is considered. For respective magnetic fields of a strength up to ten teratesla atomic nuclei exhibit linear magnetic response due to the Zeeman effect. Such nuclear reactivity can be described in terms of magnetic susceptibility [1]. Susceptibility maxima correspond to half-filled shells. The neutron component rises linearly with increasing shell angular momentum, while the contribution of protons grows quadratically due to considerable income from orbital magnetization. For a case j = l + 1/2 the proton contribution makes tens of nuclear magnetons and exceeds significantly the neutron values which give several units. In a case j = l – 1/2 the proton component is almost zero up to g-shell. Respectively, a noticeable increase in the generation of corresponding explosive nucleosynthetic products with antimagic numbers is predicted for nuclei at charge freezing conditions. In the iron group region new seeds are created also for the r-process. In particular, the magnetic enhancement of the volume of 44Ti isotopes is consistent with results from observations and indicates the substantial increase in the abundance of the main titanium isotope (48Ti) in the Galaxy’s chemical composition. Magnetic effects are proved to result in a shift of the r-process path towards smaller mass numbers, and an increase in the volume of low mass nuclides in peaks of the r-process nuclei.

Speakers: Alina Ulanova (Russia) , Mr Vladimir Kondratyev (JINR)

KoNuSy.doc

10:20 INCOHERENT NEUTRAL PION PHOTOPRODUCTION ON THE TENSOR-POLARIZED DEUTERON AT VEPP-3

The results of measurement of the T20 component tensor analyzing powers in incoherent π0-meson photoproduction on the deuteron in the proton energy range of 50–150 MeV are presented. Experimental statistics of the reaction under study was isolated from the experiment that was designed to investigate coherent neutral pion photoproduction on deuteron [1-3]. In this experiment, protons and two photons were recorded by the upper and lower arms of the detecting system, respectively. The measured asymmetries of the yields with regard to the change in the sign of tensor polarization of deuterons were used to calculate the T20 component of the tensor analyzing power of the reaction under investigation. A detailed description of the experimental setup and detection equipment is provided in [1- 3].
The obtained experimental data are compared with the results of statistical simulation. The event generation was followed by verification that it belongs to the permissible region of the kinematic phase space. After the generation of independent kinematic variables, the reaction amplitude was calculated. The model described in [4] was used to calculate the amplitude of the neutral pion photoproduction. In the framework of the model, the quasi-free pion photoproduction on nucleons that form the deuteron and the contribution of nucleon-nucleon and pion-nucleon rescattering were considered. The measurements cover the photon energy range of (300-600) MeV. In general, there is a qualitative agreement between experimental and available theoretical predictions. It is planned to give further attention to extraction of the experimental data on the reaction from the experimental statistics accumulated at VEPP-3 in 2021 using the photon tagging system.

1. Rachek I.A. er al. // Few-Body Syst. 2017. V. 58. P. 28
2. Gauzshtein V.V. et al. // European Physical Journal A. 2020. V.56. P.169.
3. Gauzshtein V.V. et al. // Modern Physics Letters A. 2021. V. 36. P. 2150199
4. Fix A., Arenhövel H. // Phys. Rev. C. 2005. V. 72. P. 064005.

Speaker: Vyacheslav Gauzshtein

tesis_Gauzshtein.docx

10:40 RELATIVISTIC INVESTIGATION OF LOW NUCLEON SYSTEMS IN THE FORMALISM OF BETE-SALPETER-FADDEEV

The relevance of the study of few-nucleon systems is motivated by the fact that there is a large amount of experimental data for the reactions of nucleon scattering on deuterons, both elastic and inelastic. New corresponding experiments with increased accuracy and at high energies are also planned (JLab, NICA). Accordingly, a theoretical study is required. There are a large number of theoretical studies of three-nucleon systems, but at low and medium energies. Most of them are based on the Faddeev equation and its modifications. One of the main problems of modern physics of low-nucleon systems is their theoretical study at high energies. One of the approaches used in this paper to study few-nucleon systems (primarily three-nucleon nuclei) is the Bethe-Salpeter-Faddeev (BSF) formalism [1-2]. Within the framework of this approach, the binding energy of three-nucleon nuclei and their electromagnetic form factors were calculated [3-6]. The calculations were carried out using various nucleon-nucleon interaction potentials and various models of nucleon form factors. Comparison of these calculations with calculations within the framework of other approaches and with experimental data shows that these studies are in good agreement with experiment. So for the binding energy of the triton, the experiment gives the value 8.48 MeV, the solution of the nonrelativistic equation - 11.55 MeV, the calculation using the BSF equation - 8.44 MeV, which is much closer to the experiment. Based on this, one can reasonably assume that this approach will lead to valuable results in the case of scattering reactions as well.

1.G.Rupp and J. A. Tjon // Phys. Rev. C. 1988. V. 37. P. 1729.
2.G.Rupp and J. A. Tjon // Phys. Rev. C. 1992. V. 45. P. 2133.
3.S. G. Bondarenko, V. V. Burov, S. A. Yurev // Phys. Part. Nucl. Lett. 2018. V.15. P. 417.
4.Бондаренко С.Г., Буров В.В., Юрьев С.А. О вкладе парциальных P- и D- состояний в энергию связи тритона в формализме Бете-Солпитера-Фаддеева. // ЯДЕРНАЯ ФИЗИКА, 2019, том 82, №1, с. 1–7.
5.Bondarenko S.G., Burov V.V., Yurev S.A. Relativistic rank-one separable kernel for helium-3 charge form factor. // Nucl. Phis. A., 2020, V. 1004, P.122065.
6.Bondarenko S.G., Burov V.V., Yurev S.A. Trinucleon form factors with relativistic multirank separable kernels. // Nucl. Phis. A., 2021, V. 1014, P.122251.

Speaker: Sergey Yurev (JINR)

Nucl_abstract_Yurev_2022.rtf

11:00 ON THE ELASTIC ELECTROWEAK SCATTERING OF POLARIZED LEPTONS BY SPIN 7/2 NUCLEI

In [1,2], in the framework of a general approach to the covariant description of the structure of half-integer spin nuclei, analytical expressions were found for the multipole expansion of the structure functions in the differential cross section for elastic scattering of longitudinally polarized leptons
.

Speaker: Dr Minikhan Safin (Peoples' Friendship University of Russia)

M. Ya. Safin.docx

11:10 Improved study of the collisional quenching of the pionic helium long-lived states

The existence of long-lived states in exotic helium atoms (π^-,К^-,p ̅-He^+) predicted by Kondo [1] about 60 years ago made it possible to conduct various series of unique high-precision laser spectroscopic experiments: thus, direct observations of E1-transitions between anti-proton helium states and M1-transitions between its superfine structure levels [2-4] were performed. Then similar experiments were continued on pionic helium atoms, where it was possible to observe transitions between atomic states [5,6]. The purpose of the conducted experiments is to obtain highly accurate fundamental characteristics of quantum objects: the antiproton magnetic moment, and upper limits on laboratory constraints on the muon antineutrino mass.
To interpret the obtained results, many theoretical questions arise; in particular, the very possibility of carrying out high-precision laser spectroscopic experiments with hadronic helium atoms depends on the destruction rate of metastable states during collisions in a medium. The rate of Stark collisional quenching of highly excited states is the highest. We use the Potential Energy Surface (PES) of three-electron π^- He^+-He system in which the three electrons move in the field of three heavy particles (two α-particles and π^-) to obtain an interaction between the colliding systems and then the rates. The PES was calculated by Unrestricted Hartree-Fock (UHF) method in Dunning's aug-cc-pV5Z basis with counterpoise correction and with account of electron-electron correlations by Moller-Plesset (MP2) method.
The numerical calculations of PES and then the numerical solution of the system of close-coupling equations are improved, especially in the region of small distances between the colliding π^- He^+-He subsystems, where some peculiarities and unusial behavior arise due to the strog interchannel interaction, and whose contribution to the rates of collisional transitions is significant. The cross sections for these transitions are systematically calculated, and the obtained results are compared to the experimental ones.

[1] G.T. Condo, Phys. Lett. 9 (1964) 65.
[2] M. Iwasaki, S.N. Nakamura, K. Shigaki, et al. Phys. Rev. Lett. 67 (1991) 1246.
[3] T. Yamazaki, N. Morita, R.S. Hayano, E. Widmann, J. Eades, Phys. Reports 366 (2002) 183–329.
[4] R.S. Hayano, M. Hori, D. Horvath, E. Widmann, Rep. Prog. Phys. 70 (2007) 1995-2065.
[5] M. Hori, H. Aghai-Khozani, A. Soter, A. Dax, D. Barna, Nature 581, (2020) 37.
[6] M. Hori, H. Aghai-Khozani, A. Soter, A. Dax, D. Barna, Few-body systems 62, 1 (2021).

Speaker: S.N. Yudin

328-Тезисы Ядро 2022 (англ.).docx

Nucleus22Slides.pdf

10:00 → 11:30 Poster session: Nuclear technology and methods in medicine, radioecology.

10:00 ESTIMATES OF THE EXPECTED AVERAGE ANNUAL EFFECTIVE DOSE OF NATURAL RADIATION BACKGROUND OF EMPLOYEES IN THE ADMINISTRATIVE BUILDING, TAKING INTO ACCOUNT THE DISTRIBUTION OF RADON AND ITS DECAY PRODUCTS

Radium is the most radiotoxic natural radionuclide, since small amounts of it can accumulate in bone tissue, damaging the bone marrow and mutating bone cells [1]. Radon is a decay product of radium and is ubiquitous in the biosphere and present in soils and building materials. Most people are most exposed to radon in residential and industrial buildings. It accounts for about half of the total human exposure dose from natural sources. Radon can damage the DNA of the respiratory epithelium, and radon exposure is suspected to be the cause of lung cancer [2]. Significant health effects have been observed among uranium mine workers exposed to high levels of radon. They found a link between exposure to radon and its decay products and an increased risk of developing lung cancer. Despite this, it remains unclear what impact household exposure to radon has on the development of lung cancer.
The purpose of this work was to estimate the dose load from natural sources of radiation based on monitoring measurements of the topology of the distribution of radon isotopes in a building located near a tectonic fault. The measurement was carried out using a radon radiometer “Ramon-02” in an administrative building located near a tectonic fault from February 2021 to February 2022 in Almaty. The experiments were carried out in rooms with a volume of 128.38 $m^3$ with a ceiling height of 2.6 m and located in the basement, on the third and fifth floors. During the experiment, the concentration of radon activity averaged 189.59 $Bq•m^{-3}$ for the basement, 23.78 $Bq•m^{-3}$ for the third floor and 35.01 $Bq•m^{-3}$ for the fifth floor. In addition, fluctuations were observed in the range from 59.9 to 568.9 $Bq•m^{-3}$ for the basement, from 12.2 to 33.6 $Bq•m^{-3}$ for the third floor and from 16.2 to 71.8 $Bq•m^{-3}$ for the fifth floor.
Based on the data obtained, the doses from radon and its decay products received by students and faculty members who are in classrooms during the day, month and year were calculated. Calculations showed that the annual effective dose in this administrative building (working time-2000 hours/year) ranged from 0.5 mSv/year (for the fifth floor) to 2.2 mSv/year (for the basement).
This research is funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP09058404).

1. M. Jankovic, D. Todorovic, and J. Nikolov, Appl. Radiat. Isot. 70, 2703 (2012).
2. R. Hubaux, K. Enfield, S. Lam, W. Lam, V. Martinez, Environ. Health. 11, 89 (2012).

Speaker: Yuliya Zaripova (al-Farabi Kazakh National University)

Zaripova_1.docx

10:20 STUDY OF GENETIC EFFECTS IN BIOASSAYS ARISING FROM RADIATION THERAPY USING A LINEAR ACCELERATOR ELEKTA AXESSE

Currently, gamma radiation is widely used in the treatment of cancer. In particular, in the treatment of oncological diseases, the ELEKTA AXESSE medical linear accelerator is used, which forms beams of gamma rays with energies of 10 MeV and 15 MeV. Gamma radiation of such energies is highly penetrating and thus capable of being absorbed in a sufficiently large volume of biological material. Thus, in this work, the aim is to study the appearance of radiation defects from various doses of irradiation with gamma rays with energies of 10 MeV and 15 MeV. Such a study is of interest in studying the prolonged effect of gamma therapy on body cells.
This paper presents the results on the frequency of mutations induced by beams of gamma rays with energies of 10 and 15 MeV. The relative exposure doses were 2Gy, 5Gy, 10Gy, 15Gy, 20Gy and 30Gy. The electronic accelerator Elekta Axesse of the oncological center “Sunkar” (Almaty) was used as a source of gamma quanta. A study of the genotoxic effects of gamma radiation was carried out using Drosophilamelanogaster. A series of fly larvae after irradiation were placed in test tubes with a medium for crossing irradiated adults. Each tube in the tests was subjected to visual analysis after the complete departure of the generation to identify mutations. Morphoses were chosen as the main criterion for assessing the mutagenic and teratogenic effects of gamma radiation on Drosophila. The formation of morphoses is one of the properties of conditional mutations that are not associated with the primary structure of DNA and occur in regulatory genes responsible for the formation of traits of intraspecific similarity. In this case, the stress factor was gamma radiation, and the appearance of morphoses demonstrated teratogenic effects or disturbances in the genetic development program. In addition to morphoses, cases of sterility or a decrease in the fertility of adults were found, which is evidence of the mutagenic effect of irradiation, since such a phenomenon was not observed in the control. The teratogenic properties of gamma radiation were revealed, expressed in the appearance of morphoses or asymmetric ugly disorders of the soma morphology. The data obtained indicate that gamma quanta have pronounced mutagenic and teratogenic properties, i.e. is genotoxic. As a result of the experiments, the types of induced mutations were determined, and the significance of genetic effects for various energies of gamma rays was assessed.
This research has been funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP09258978).

Speaker: Mirgul Bigeldiyeva (al-Farabi Kazakh National University)

nucleus-2022-abstract-2.docx

10:40 STUDYING THE DOSE LOAD ON THE RESPIRATORY SYSTEM FROM HEAVY NATURAL RADIONUCLIDES DURING TOBACCO SMOKING

According to the ICRP (publications No. 50 and No. 65), radon and its decay products (Rn-DP) contribute more than 50% to the total radiation background. In Kazakhstan, cancer incidence rates remain among the highest among the CIS countries [1-2] and 28831 new cases were detected in 2020 [3]. Currently, it has been proven that the main cause of lung cancer is smoking [4]. However, despite the fact that the first place as a cause of lung cancer is occupied by tobacco smoking, the second place is occupied by the inhalation of radon and Rn-DP. Toxic chemicals in tobacco smoke are one reason why cigarettes cause cancer, but radioactive heavy elements also play a significant role in them. They accumulate in tobacco leaves at the time of their vegetation due to absorption from the soil and air, and the rate of absorption depends on the pH of the soil. The decay product of radon, Pb-210, plays an important role in human radiation exposure, since it has a long residence time in the body [5]. This contributes to an increase in the dose of internal radiation and increases risk of lung cancer. For this reason, conducting studies on the quantitative assessment of the concentration of natural beta-radionuclides in the lungs due to smoking as one of the causes of the carcinogenic effect is an urgent task.
In this work, the authors performed a quantitative assessment of the concentration of natural beta-radionuclides in six samples of the most popular tobacco products in the Kazakhstan. The beta activity concentrations of the samples were measured by beta spectrometry using a scintillation detector. The results of the preliminary analysis of this work show that the lower threshold for the activity of beta-radionuclides in the tobacco of one cigarette is 60 mBq. A person who smokes one pack a day (20 cigarettes) inhales an average of 120 mBq. The annual effective doses were calculated based on the intake of Pb-210, as having the greatest danger among other beta radionuclides, and amounted to 39 µSv/year for a person who smokes one pack per day.
This research is funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP09058404).

1. A. Jemal, R. Siegel, and K. Miller, C.A. Cancer. J. Clin. 66(1), 7 (2016).
2. Indicators of the oncological service of the Republic of Kazakhstan for 2019 https://onco.kz/o-rake/ponimanie-raka/statistika-raka/
3. J. Ferlay, M. Ervik, F. Lam, M. Colombet, Global Cancer Observatory. Lyon, France: International Agency for Research on Cancer. Available from: https://gco.iarc.fr/today
4. K. Nurgaziev, G. Seitkazina, D. Baypeisov, G. Seisenbaev, and A. Zhylkaidarova, Indicators of oncology service in the Kazakhstan for 2017. Almaty: KazIOR, 2017. 138 p.
5. B. Swift, Forensic Sci. Int. 98, 119 (1998).

Speaker: Mirgul Bigeldiyeva (al-Farabi Kazakh National University)

Bigeldiyeva_2.docx

11:00 STUDIES OF RADON CONCENTRATION IN RESIDENTIAL AND PUBLIC BUILDINGS LOCATED IN THE TIEN SHAN FOOTHILLS AND THE NEVA LOWLAND AREAS

The large territories of the Republic of Kazakhstan and the Russian Federation are characterized by a different radiation environment due to the mining (coal, gas, non-ferrous metals and uranium), the geological conditions, seismic activities and mountainous areas. In this case, the radiation environment is influenced by radioactive gases (radon, thoron), together with their decay products, and radioactive aerosols formed in natural chains of uranium and thorium series. Thus, one of the most important tasks of radioecological research is the analysis of radon concentration in residential and public buildings. Radon enters the building from the ground, through foundations and floors, or directly from building materials. As a result, a rather high radiation background can be registered in the building. Especially if the house has the high concentration of uranium-thorium series radionuclides, or if materials with a high uranium concentration were used in its construction. Also, if there is a positive temperature difference inside and outside the building, a pressure gradient arises and an additional mechanism appears that contributes to the entry of radon. This mechanism is usually much more important than the diffusion transfer of radon [1].
Therefore, it seems to be interesting to study the concentrations of radon and its decay products in residential and administrative buildings, and especially in newenergy-efficient buildings [2]. In present work, the objects of research were buildings located in the foothill regions of the Tien Shan (Almaty region), because tectonic faults and the rocks are additional sources of radon. On the other hand, it would be interesting to compare experimental data on radon concentration obtained in buildings located in mountainous areas with data obtained in buildings built in the Prinevskaya lowland area (with the corresponding geological structure) at the zero mark of the height and depth reference system ( region of St. Petersburg).
In this work, data on radon volume activity were obtained and analyzed in the period from February 2021 to February 2022 in housing and public buildings of Almaty and St. Petersburg. As a result, the radon concentration distributions were obtained at all levels of administrative and residential buildings. The dependences of radon volume activity on temperature, humidity and pressure were analyzed. Also, in some local places the high radon volume activity was detected. Such radon «jets» can add an additional radiation load to the total exposure dose for the population from natural radiation sources.
This research has been funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP09258978).

1. V.I. Zherebchevsky, N.A, Maltsev, «Measurement of the content of radon and thoron in samples», SPb .: VVM Publishing House, ISBN 978-5-9651-1299-9, 2020.
2. Yarmoshenko, I.V., Onishchenko, A.D., Malinovsky, G.P. et al. Radon concentration in conventional and new energy efficient multi-storey apartment houses: results of survey in four Russian cities, Nature, Sci. Rep. 10, 18136 (2020). https://doi.org/10.1038/s41598-020-75274-4

Speaker: Dr Vyacheslav Dyachkov (al-Farabi Kazakh National University)

nucleus-2022-abstract_VZh_corr2.docx

11:10 APPLICATION OF LITHIUM-DOPED CRYSTALS IN TASKS OF SEPARATE DETECTION OF GAMMA-RAYS AND NEUTRONS

Modern trends of radiation control instruments development require creation of highly efficient high autonomy detection devices with minimal dimensions, which allows radiation safety services to perform inspection of various objects in the most efficient way.
Currently, 3He counters are used in most of the neutron detection devices. An alternative is the use of lithium-doped crystal scintillators, which combine the functions of gamma spectrometry and neutron detection. The main representatives of detectors of this class are CLYC [Cs2LiYCl6(Ce)], NaIL [NaI (Li+Tl)] and CLLB [Cs2LiLaBr6(Ce)].
The ATOMTEX SPE is developing probes for separate detection of neutron and gamma radiation on the basis of CLYC and NaI(Li+Tl) detectors. According to the results of the studies, NaI(Li+Tl) scintillator is more promising for use in the absence of strict requirements to the resolution capability due to simpler discrimination of radiation types and lower cost of the detector.
The use of the CLYC scintillator is associated with the need to solve the problem of optimal light collection, because this scintillator has light output twice less than NaI(Li+Tl) and its emission spectrum is shifted to UV region. Also the process of classification of the registered radiation is more complicated and requires the use of digital signal processing methods.
The report presents the analysis of pulses of CLYC, NaI(Li+Tl) detectors obtained from the photomultiplier tube and considers methods of pulse processing for separate detection of gamma-radiation and neutrons on these scintillators. The prospects of application of separate gamma-radiation and neutron detection units for various tasks are considered.

Speaker: Mr Ilya Lagutskiy (ATOMTEX SPE)

Lagutskiy Nucleus-2022.pdf

Nucleus-2022 Lagutskiy Abstract.docx

11:10 APPLICATION OF SRI2(EU) CRYSTAL IN PROBLEMS OF GAMMA-RADIATION SPECTROMETRY

APPLICATION OF SRI2(EU) CRYSTAL IN PROBLEMS OF GAMMA-RADIATION SPECTROMETRY
D. I. Komar, I. A. Lagutskiy, A. V. Antonov, V. I. Antonov
ATOMTEX SPE, Minsk, Belarus
E-mail: info@atomtex.by

According to the requirements of international standards, the energy resolution of spectrometric equipment for radiation monitoring systems should be less than 4.5%. The Rosenergoatom standard STO 1.1.1.01.001.0875-2017 requires a spectrometric detection unit with a resolution of not above 4.5% for 137Cs radionuclide to be used at the radiation monitoring station ASCRO. Also, the ANSI N42.34-2015 standard introduces a requirement for the energy resolution of the spectrometric channel of radionuclide composition identifiers to be no more than 4%.
ATOMTEX SPE has developed a spectrometric detection unit based on the SrI2(Eu) scintillation detector with dimensions Ø38×38 mm. According to the results of the spectrometric studies of the detection unit, the typical resolution was 3.3% for the 662 keV line of the 137Cs radionuclide.
To minimize the influence of external factors on the characteristics of the spectrometric path, classical LED stabilization is used. To correct superimposed pulses from the ADC, pulse superposition rejection is used.

Speaker: Damian Komar

Komar_DI_poster.docx

11:10 REFERENCE FIELDS FORMED AT THE DOSIMETRIC BETA-RADIATION FACILITY

To reproduce absorbed dose units, directional and individual dose equivalents of beta radiation in tissue-equivalent matter, and to transfer the obtained units to working standards and dosimeters of beta radiation, beta radiation dosimetry units are used, which form the reference fields from radionuclide beta radiation sources.

Speaker: Руслан Титков

Titkov_poster.docx

11:10 THE DOSE CALCULATION BASED ON CBCT IMAGES FOR LONG TARGET CASES: A PHANTOM STUDY

Cone-Beam Computed Tomography (CBCT) images have different normalization of the Hounsfield Units (HU), artifacts and a limited field of view. That is all creates difficulties for the CBCT dose recalculation. In this study we assess the possibility of using several CBCT sets for replanning or further dose evaluation for long target cases.
Doses were calculated in the anthropomorphic phantom CIRS ATOM ® using Monte-Carlo algorithm in MIM SureCalc® MonteCarlo (Cleveland, USA). Planned dose at the CT images (rCT) was considered as reference, doses at different CBCT images were considered as evaluated. The phantom was scanned with the standard CT mode (120 kV); the targets (Brain and Spinal Cord) were contoured and treatment plan was created.

Obtained CBCTs for four different regions of the phantom (head, chest, abdomen, and pelvis) were united into one combined series (cCBCT) for futher dose calculation. Also all areas were scanned using the only low-dose CBCT protocol to get another low-dose cCBCT. HU to electron density correction was applied for both cCBCT and low-dose cCBCT, assigning density to bones and lungs was applied only for low-dose cCBCT. Reference and evaluated dose distributions were compared using gamma criteria of 2 % 1 mm. The number of points that satisfy this gamma-criterion is 87.38 % between rCT and low-dose cCBCT; 94.08 % between rCT and low-dose cCBCT with assign lungs and bones densities; 96.78 % between rCT and low-dose cCBCT with imbedded correction HUs; 98.72 % between rCT and cCBCT captured on different protocols corresponding scan areas with imbedded HUs correction. Plans recalculation using several CBCTs for long targets is difficult but feasible task and provide possibilities for adaptive radiotherapy.

Speaker: Mrs Anastasiya Lisovskaya (Dmitry Rogachev National Medical Research Center Of Pediatric Hematology, Oncology and Immunology, Radiotherapy Department)

PosterLisovskaya.pdf

Ядро2022.docx

11:20 Agility multileaf collimator parameters optimization in the independent dose calculation system

The MIM SureCalc® is MonteCarlo Plan verification system (MIM Software Inc. Clevland, OH, USA) used to provide an independent dose calculation calculation check of radiotherapy treatment plans. These module include a voxel based Monte Carlo engine to calculate the dose in the patient. The input data are DICOM RT Image, RT Structure and RT dose derived from treatment planning system. The algorithm uses virtual source models, which are analytically expressed phase space models generated from BEAMnrs [1]. The model of the linac is created by the software manufacturer based on the data provided by the users (depth dose distributions, beam profiles, and radiation output factors)
The aim of this study was to assess the MIM SureCalc® MonteCarlo Plan verification module and optimize the calculation parameters according the measured data obtained using Elekta linear accelerator equipped with Agility™ multileaf collimator (MLC).
The modeling accuracy of MLC was assessed by comparing the calculated and measured dose distributions in L-shaped test radiation fields (four bordering segments in the form of the letter “L”). The measurements were performed with the massive of ionization chambers MatriXX (IBA Dosimetry). The modeling of the MLС offsets (the difference between the given leaf position and its actual value), as well as the leaf groove values (characteristic of the field edge formed by the side surfaces of the MLC leaf) was evaluated using Gamma analysis [2].
The optimization began with all parameters set to their default value. Comparison of the calculated test fields with the measurements showed that correction of the leaf groove leakage and offset values are required. The offset value of 0.1 mm was selected that best replicated measurements with the Agility™ MLC. Correction of leakage values was possible only by changing the virtual source model and required additional actions from the manufacturer.
The adjustment of the above parameters resulted in improved 2D Gamma of 2% 1 mm analysis passing rates up to 98.0% when applying the global and 95.2% when applying the local normalization.
The appropriate optimization of MLC parameters responsible for the properties of a particular device makes it possible to achieve high accuracy in MIM SureCalc® MonteCarlo Plan calculation.

1. Rogers DW, Faddegon BA, Ding GX, Ma CM, We J, Mackie TR. BEAM: a Monte Carlo code to simulate radiotherapy treatment units. Med Phys.—1995.—V.22.—P.503-24
2. Daniel A. Low, William B. Harms, Sasa Mutic, James A. Purdy A technique for the quantitative evaluation of dose distributions // Med. Phys.—1998.—V.25.— P.656-661

Speaker: Mrs Anna Loginova (Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia)

Loginova-nucleus-2022-abstract-mlc.docx

PosterLoginova.pptx

10:00 → 11:30 Poster session: Synchrotron and neutron radiation sources and their use in scientific and applied fields

10:00 A LINEAR ELECTRON ACCELERATOR – TOP-UP INJECTOR FOR THE 4TH GENERATION SPECIALIZED SYNCHROTRON RADIATION SOURCE USSR

emphasized textThe 4th generation synchrotron light source called Ultimate Source of Synchrotron Radiation (USSR-4) is under development at the moment in Russia [1]. Parameters of X-ray radiation of advanced modern Synchrotron Radiation Sources – brightness, coherence and temporal resolution – make it possible to provide experiments to study the structure of the widest range of objects in a variety of disciplines at a qualitatively new level compared to previous generation’s sources. New 4th generation source design will be the one of the largest world scientific centers and will require the innovations and evolution in the domestic technologies of magnetic and vacuum systems, the solution of new problems in materials science and instrument engineering.
General facility layout includes 6 GeV main storage ring and a linac for top-up injection. Thus, it is proposed to use the same linac with two RF-guns. First of them will RF photogun and can be used to generate the drive beam for FEL. The second one will RF-gun with thermionic cathode can be used for injection into storage ring. Both injectors will operate with the same regular part of the linac which consists of 110 identical regular sections (see Fig. 1). The planning to have the transverse emittance of 70 pm·rad for the storage ring and less than 1 nm∙rad for a FEL.

Fig. 1. Layout scheme of the 6 GeV top-up injection linac.

Development of a general layout of the top-up linac with the aim to minimize of the beam energy spread and transverse emittance at the exit, optimization of geometrical and electrodynamical parameters of accelerating structures and analysis of the front-to-end beam dynamics in this linear accelerator will discuss in the report. All results of the beam dynamics simulation carried out using the BEAMDULAC package developed at the Department of Electrophysical Facilities of NRNU MEPhI [2].

1. V.S. Duybkov et al, Proc. of RuPAC’2021, TUPSB26 (2018), pp. 280-282.
2. E. Masunov, S. Polozov, Nucl. Instrum. Meth. A 558, (2006)

Speaker: Mr Ilia Ashanin (NRNU MEPHI)

Ashanin I.A. abstract.doc

10:20 INVESTIGATION OF CRYSTAL AND MAGNETIC STRUCTURES OF MULTIFFERROIC MATERIAL UNDER HIGH PRESSURE

Magnetoelectric multiferroics, where a ferromagnetic and a ferroelectric order coexist and are coupled in a single phase, have been a hot topic in condensed matter physics for a long time owing to their ability to facilitate next generation applications. Mainly, understanding of the magnetoelectric effect in single-phase materials is one of the most exciting and interesting topics of research in the solid-state physics. Pb(Fe2/3W1/3)O3 (PFWO) belongs to the family of Pb-based multiferroic relaxor ferroelectric complex perovskites (AB′1−xB′′xO3). It is generally accepted that this material exhibits a disordered perovskite structure, where Fe3+ and W6+ ions are randomly distributed at the centers of the BO6 octahedra. However, recently studies have revealed the presence of the set of superlattice reflections, which indicates some kind of B-cation ordering in PFWO which had been thought to be totally disordered. It was found that the crystal structure of PFWO should be described by a partly ordered cubic perovskite (i.e. Fm−3m), also, the weak ferromagnetic properties and excess magnetic moment of PFWO can be understood based on non-random distribution of Fe cations between the 4a and 4b sites. Despite intensive studies, understanding the exact nature of its multifunctional properties of PFW has remained a challenge for decades. The knowledge of relationship between magnetic and crystal structure of such compounds, which can be obtained from high-pressure investigations, is very essential for understanding the nature and mechanism of physical phenomena observed in it. In addition, the detail studies of structural changes under extreme conditions were not carried out.
In present work was performed neutron diffraction studies of PFWO at high pressures and low temperature. Neutron powder diffraction measurements at high pressures up to 7 GPa were performed with the DN-12 diffractometer at the IBR-2 high-flux pulsed reactor [FLNP, JINR, Dubna, Russia] using the sapphire anvil high-pressure cell. In order to improve the understanding of the lattice instabilities the Raman spectroscopy studies of the vibration spectra of the compound under pressure up to 30 GPa were performed. The crystal structure of this compound also has been studied by X-ray diffraction at high pressures. Pressure dependences of the volume, unit cell parameters and of magnetic moments of antiferromagnetic (AFM) phase, Neel temperature were also calculated. With increasing temperature and pressure, slight decreasing of the magnetic moments of iron ions in PFWO were observed, however, although the crystal structure remains stable up to high pressures with a space group Pm-3m. Some Raman modes have been found on the Raman spectra, which in such compounds are correlated with the existence of nanoregions, however, with increasing pressure, these modes noticeably widen and vanish.
The work was supported by the JINR Grant for young scientists 22-402-03.

Speaker: Olga Lis (Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research)

Lis_Poster.docx

Nucleus_Poster_Lis.pdf

10:40 A LINEAR ELECTRON ACCELERATOR WITH AN ENERGY OF 8-50 MEV WITH INJECTION FROM AN ELECTRON SOURCE BASED ON CLUSTER PLASMA SYSTEMS

The problem of increasing of the acceleration rate in linear electron accelerators has been one of the key problems for modern accelerator physics for many years. The physical limit of the accelerating field strength for normal (50 - 100 MV/m) and superconducting accelerating structures (over 200 MV/m) has been practically reached, and therefore various new acceleration schemes are being considered, primarily plasma acceleration and wakefield acceleration [1].
It seems interesting to consider a system in which one can try to bypass the limitations inherent in photoguns (the dominant effect of the space charge in the near-cathode region during injection) and acceleration in the laser-plasma channel (low electron transmission coefficient in the acceleration mode, wide energy spectrum (up to 10%) and low repetition rate pulses, limited by the capabilities of laser systems) [2]. Many works have appeared devoted to the preliminary modulation of the beam in the plasma channel, which makes it possible to improve the spectrum of accelerated electrons by a factor of approximately 3–4 [3].
It is proposed to consider the possibility of using a bunch generated in a laser-plasma channel for injection into a traditional structure based on RF cavities. It is supposed to show that a plasma source of electrons based on cluster plasma can produce a short (from 0.1 to 1.0 ps) bunch of electrons with an energy of several hundred keV [4], which makes it possible to consider such a source as an alternative to the photocathode. Next, the beam must be captured into the acceleration mode in a normally conducting section operating on a standing wave and accelerated to an energy of 50 MeV with adjustable energy.
The features of such a source are considered, including the possible energy spectrum, and features of an electron bunch capturing with the achieved parameters in the acceleration mode will discuss in the report. All results of the beam dynamics simulation carried out using the BEAMDULAC package developed at the Department of Electrophysical Facilities of NRNU MEPhI [5].

1. Ya. Fineberg, Atomic Energy 6, p. 341 (1959)
2. V. Leurent, C. Clayton et al., Proc. of EPAC’08 (2008), pp. 2809–2811.
3. S. Polozov, V. Rashchikov, Cybernetics and Physics, 7 4 (2018), pp. 228–232.
4. A. Shkurinov et al., Journ. of the Optic. Soc. of America B, 38 11 paper 3515 (2021)
5. E. Masunov, S. Polozov, Nucl. Instrum. Meth. A 558, (2006)

Speaker: Ilia Ashanin (NRNU MEPHI)

Ashanin I.A. abstract plasm ii.doc

11:00 Determination of neutron detection efficiency of DEMON and PARIS detectors using a $^{252}$Cf source

The results of measuring the energy distribution of neutrons emitted from the $^{252}$Cf source by the DEMON and PARIS detectors are presented. DEMON (DEtecteur MOdulaire de Neutrons) is scintillator detector widely used for neutron detection [1]. PARIS (Photon Array for the studies with Radioactive Ion and Stable beams) is new-built detector consisting of CeBr$_3$ - NaI(Tl) phoswich scintillators [2].
The energies of the neutrons were measured by the Time – Of – Flight (TOF) method where a semiconductor detector was used for fission fragment detection and START-pulse generation for the TOF measurements. The STOP pulses for TOF measurements were generated by DEMON and PARIS detectors, respectively.
The energy dependence of the neutron efficiency for DEMON and PARIS detectors at the $E_n = 0.7 ÷ 7$ MeV neutron energy range were determined by comparing the measured data with standard $^{252}$Cf spectrum [3].

1. I. Tilquin et al., Nucl. Instr. Meth. A 365, 446 (1995).
2. A. Maj et al., Acta Phys. Pol. B 40, 565 (2009).
3. W. Mannhart, Proc. of IAEA Consulting Meeting, INDC(NDS)-220, p. 305 (1989).

Speaker: Olga Saiko (Dubna State University, Dubna, Russia)

nucleus-2022-abstract-Saiko.docx

11:10 MEPHI’S OPTION OF LAB SCALE COMPTON SOURCE

A development and construction of comparatively cheap and compact (several meters scale) X-ray sources is possible with the help of inverse Compton scattering of laser photons on an electron bunch. Such sources can be used in the field of materials science (new materials, diagnostics of nanostructures at the atomic level), research of nano- and biosystems, medicine and pharmacology (new drugs R&D), physics and chemistry of fast-flowing processes (burning, explosion). It is suggested that compact storage synchrotron will operate with normal conducting S-band top-up linac. Linac will provides bunches with tunable energy in the range of 20-60 MeV to generate the photon flux with tunable energy [1, 2]. The use of a storage ring provides the following advantages: comparatively high average intensity of the generated photon flux, high brightness, photon beam energy tuning in a wide range, high degree of monochromaticity and coherence of the generated photons. There are current results of the design of a compact storage ring for generating the photons in the energy range of 5-30 keV and investigations of the development of relativistic picosecond electron beam dynamics instabilities in the report.

1. V. S. Dyubkov et al., Beam dynamics investigation for a new project of compton back scattering photon source at NRNU MEPhI // 12th IPAC, May 2021, Online, Brazil. MOPAB042.
2. V.S. Dyubkov, S.M. Polozov, Storage ring design and beam instabilities investigation for MEPHI’s photon source // Proc. of RuPAC 2021, Alushta, Russia, 2021, P. 277-279.

Speaker: Prof. Sergey Polozov (NRNU MEPhI)

nucleus-2022-abstract-2.docx

11:30 → 13:50 Plenary session

Convener: Grigory Feofilov (Saint-Petersburg State University)

11:30 FOURTH GENERATION LIGHT SOURCE SKIF IN NOVOSIBIRSK: STATUS AND PERSPECTIVES

SKIF is the Russian acronym for Siberian Circular Light Source – a new fourth generation synchrotron light facility that is now under development in Novosibirsk (Russia). SKIF consists of 200 MeV linear accelerator-preinjector, 3 GeV booster synchrotron (154 m in circumference), 3 GeV electron storage ring (476 m) with extremely low natural horizontal emittance of 73 pm⋅rad and number of scientific and engineering infrastructures [1]. Fig.1 shows the SKIF buildings and premises with the main ring-shape building in the middle.

Fig. 1. General view of the SKIF light source facility.

SKIF storage ring has 16-fold symmetry magnetic lattice with 16 6-m-long straight sections; two sections are for RF system and injection others 14 will accommodate different insertion devices (including superconducting ones) delivering high brightness X-rays to up to 30 experimental stations. First six stations are under development now.
Here we report status of the SKIF design and manufacture including accelerator systems, experimental stations, engineering infrastructure and civil engineering.

1. Baranov G., Bogomyagkov A., Levichev E., Morozov I. and Sinyatkin S. Phys. Rev. Accel. and Beams 24, 120704 (2021).

Speaker: Prof. Eugene Levichev (BINP SB RAS)

12:05 Heavy-ion physics with CMS detector

We present a selection of very recent results by the CMS collaboration on heavy-ion physics at the LHC (CERN).

Speaker: Sergey Petrushanko (Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University)

396-nucleus-2022-abstract-Petrushanko.docx

Petrushanko_Nucleus2022.pdf

12:40 The JUNO experiment: status and prospects

Jiangmen Underground Neutrino Observatory is an experiment under construction in China. A spherical detector of 35 m in diameter filled with 20 kt of liquid scintillator and equipped with more than 17'612 (25'600) large (small) photomultipliers will provide immense statistics, high energy resolution (σ=3% at 1 MeV) and low energy threshold (0.2 MeV) making the physics program broad.
The primary goal is determination of the neutrino mass ordering and precision measurement of the neutrino oscillation parameters via observation of more than 100'000 reactor electron antineutrinos from Yangjiang and Taishan nuclear power plants. The experiment will also observe high statistics of the solar neutrinos from pp,⁷Be and ⁸B. The geo- neutrinos will be measured with uncertainty of 5%. JUNO will also be able to observe atmospheric neutrinos in sub-GeV and GeV region, diffuse supernovae neutrino background with significance of 3σ in 10 years and will be able to see the neutrinos from the core collapse supernova.
The experiment will have competitive sensitivity to the nucleon decay and the cold dark matter annihilation in the Sun.

In addition to the JUNO detector the JUNO experiment will be equipped with two satellite detectors: TAO and OSIRIS. The TAO will measure the antineutrino spectrum from the Taishan nuclear power plant with energy resolution of σ=2% at 1 MeV and statistical uncertainty of 1%. It will be able to test short baseline neutrino oscillation up to the masses of 8 eV². A new project Serappis aims to use the modified OSIRIS detector to measure the solar pp neutrinos with energy resolution of σ=2.5% and precision of few percents.

The talk will cover the status of the experiment and will provide the latest estimation of its sensitivity.

Speaker: Dr Maxim Gonchar

gonchar-juno-nucleus-2022-abstract.docx

nucleus22_gonchar_juno_v4.pdf

13:15 COMPTON DESINTEGRATION OF POSITRONIUM

The recent experiments on Compton scattering using a new experimental technique [1] gave rise to a new wave of interest in this old effect discovered 100 years ago. To describe the process of Compton decay of positronium we use the nonrelativistic A2 approximation.
We study the Compton single ionization of positronium in comparison with the same of hydrogen [2]. The initial photon energy of a few keV allows one to apply the non-relativistic approach. Interesting differences in the behavior of various differential cross sections of the process are observed. In particular, the conditions were found, under which the electron and positron move parallel to each other with equal velocities, which leads to a series of resonances (see Fig.1). This suggests that the probability of annihilation is suppressed in this continuum state, and it is likely to be a long-lived one, especially in the presence of external electric and magnetic fields.

Fig. 1. FDCS (atomic units) of Compton positronium decay versus the energy Ee(eV) of the emitted electron and the photon scattering angle θ. The photon energy is ω = 5 keV

1. M. Kircher et al. Nature Physics 16(4), 756 (2020) 2. S. Houamer et al. EPJD 74, 81 (2020)

Speaker: Prof. Yuri Popov (SINP, Lomonosov Moscow State University, Moscow, Russia; BLTP, Joint Institute of Nuclear Research, Dubna, Russia)

Compton desintegration of positronium_Popov.docx

13:50 → 15:00 Lanch

15:00 → 16:40 Applications of nuclear methods in science and technology

Convener: Dr Mikhail Merkin (SINP MSU)

15:00 Determination of the oxygen content in the investigated samples using delayed neutron counting technique

In the present work delayed neutron registration technique have been applied to the issue of oxygen content definition in the samples of the known mass and morphology. For this purpose the set up have been assembled on the neutron physical research channel of Tandem-3M accelerator of SSC RF–IPPE which consists of the charged particles beam deflection system, integrator of the current of charged particles hitting the neutron generating target, primary neutron beam monitor, spectrometer of primary neutrons, pneumatic transport system of the samples under investigation, 4π-detector of neutrons, constructed on the base of helium-3 filled proportional counters and experiment control system. Oxygen content have been determined using comparative analysis of the measurement results of the temporal dependences of delayed neutron intensity after irradiation of the control sample and investigated samples in the fast neutron flux generated in the Li(d,n) reaction from infinitely thick lithium target. Experimental procedure due to the temporary nature of delayed neutron emission phenomenon have been consisted in the carrying out the cyclic consequence of the stages of sample irradiation by neutrons generated from the target, sample movement to the neutron detector and the measurement of the temporal dependence of delayed neutron intensity.

Speaker: Konstantin Mitrofanov

162-Abstract _ 162 _ Mitrofanov _ Determination of the oxygen content in the investigated samples using delayed neutron counting technique.doc

15:20 Influence of neutron detector structural materials on fast neutron detection

Some nuclear reactions on nuclei in neutron detector structural details even so as aluminium are induced with energy increasing. Nuclear reactions induced by neutrons between 5 and 20 MeV energy are under consideration. They causes background events in gaseous and scintillation detectors with $^3$He, $^7$Li and $^10$B isotopes. The events and neatron scattering and nucleus activation disturbs measurement results, leads to detector excitation without neutrons.
Interaction of neutron with an energy of more than 5 MeV with aluminum, silicon and oxygen nuclei as the main materials of new position-sensitive detector is considered. Interaction of neutron with converter nuclei: $^3$He, $^7$Li and $^10$B is considered also.

Speaker: Dr Sergey Karaevsky (INR RAS)

Karaevsky_abstract 2022_eng_.doc

Nucleus-2022_Karaevsky_Presentation_2.ppt

15:40 USING THE TAGGED NEUTRON METHOD FOR DETERMINING THE CONCENTRATION OF CARBON IN SOIL

Monitoring the content of soil organic carbon (SOC) is one of the most important tasks in the field of global climate change, in the development and implementation of measures aimed at reducing greenhouse gas emissions [1].
Existing methods of soil analysis [2] mainly involve the selection of bulk samples and work in the laboratory, which leads to a significant complication of obtaining analytical results, to additional use of human and time resources, and in some cases to the unreliability and insufficient accuracy of the data obtained.
The tagged neutron method (TNM) [3, 4] can be used for fast nondestructive elemental analysis of various substances and materials, in particular, without sampling. The method uses neutrons with an energy of 14.1 MeV, which have a high penetrating power. An important advantage of the method is the possibility of using portable tagged neutron generators, which makes it possible to carry out field measurements.
We present some results of test measurements and model simulations, which will help to assess the accuracy limits of the method in terms of reproducibility and repeatability of determining the carbon content in mock soil samples using TNM.

1. Lal, R.: Soil carbon management and climate change, Carbon Manage., 4 (2013) 439–462, https://doi.org/10.4155/cmt.13.31.
2. England J.R. and Viscarra Rossel R.A., SOIL, 4 (2018) 101–122, https://doi.org/10.5194/soil-4-101-2018.
3. Valkovic V., 14 MeV Neutrons: Physics and Applications. CRC Press: Taylor & Francis Group; 2016, 481p.
4. Galina Yakubova, Aleksandr Kavetskiy, Stephen A. Prior, H. Allen Torbert, Tagged neutron method for carbon analysis of large soil samples, Applied Radiation and Isotopes, Volume 150 (2019)12134, ISSN 0969-8043, https://doi.org/10.1016/j.apradiso.2019.05.028.

Speaker: Yuri Kopatch (JINR)

kopatch_nucleus2022.pptx

nucleus-2022-abstract-carbon.docx

16:00 Measurement of yields and angular distributions of γ-quanta from the interaction of 14.1 MeV neutrons with oxygen, phosphorus and sulfur nuclei

The study of inelastic scattering of fast neutrons by atomic nuclei is of great importance for fundamental and applied neutron-nuclear physics. Reactions induced by neutrons are the unique source of information for describing the processes of strong interaction between nucleons. Inelastic scattering processes are used to study the characteristics of excited states of target nuclei [1]. The practical use of the (n,n'γ) reaction requires the expansion and refinement of experimental data on this process. Research on the inelastic scattering of fast neutrons has recently become more active in connection with new prospects for the production of nuclear energy using fast neutron reactors.
The purpose of the experiment was to refine the available data on the yields and angular distributions of γ-rays from inelastic scattering of 14.1 MeV neutrons by natural composition of oxygen, phosphorus and sulfur nuclei. The work was carried out within the framework of the scientific program of the international TANGRA (TAgged Neutrons and Gamma RAys) project at Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research in Dubna (Russia).
Inelastic scattering was studied by the Tagged Neutron Method [2], in which neutrons with an energy of 14.1 MeV produced in the d(t,a)n reaction are “tagged” by detecting alpha particles. Gamma quanta from the (n,n'γ) reaction were recorded by the “Romasha” multidetector system [3]. Experimental data are shown and discussed in comparison with previously published data.

1. W. Hauser and H. Feshbach. The Inelastic Scattering of Neutrons, Phys. Rev., 1952, vol. 87, p. 366., https://doi.org/10.1103/PhysRev.87.366
2. I.N. Ruskov, Yu.N. Kopatch, V.M. Bystritsky et al. Physics Procedia, vol. 64, 2015, pp. 163-170, ISSN 1875-3892, https://doi.org/10.1016/j.phpro.2015.04.022.
3. D.N. Grozdanov, N.A. Fedorov, Yu.N. Kopatch et al. IJPAP vol. 58(05), pp. 427-430, 2020, http://nopr.niscair.res.in/handle/123456789/54739.

Speaker: Dimitar Grozdanov

Grozdanov_NUCLEUS_2022.pptx

nucleus-2022-abstract-gamma_o_s_p.docx

16:20 Using Tagged Neutron Method for On-line Analysis of Materials on Conveyor

This paper discusses the application of the AGP-K conveyor analyzer to solve the problem of controlling the elemental composition of material on the conveyor. The result of the analyzer operation is given and the obtained data are discussed.
The results of using tagged neutron method for on-line analysis of materials on conveyor are presented. The method of tagged neutrons makes it possible to determine the concentrations of the desired elements inside objects contactless, due to the large penetrating power of neutrons.
The Tagged Neutron Method consists in irradiating the object of analysis with beams of fast neutrons with an energy of 14,1 MeV, which are formed in the reaction d + 3H → 4He + n. [1-3] In this reaction, the neutron and the α-particle fly apart in almost opposite directions. Therefore, by registering the α-particle accompanying the neutron, it is possible to determine the direction of neutron departure. This procedure is called tagging of neutron. A fast neutron with an energy of 14,1 MeV enters the substance of the object and interacts with the nuclei of the substance in inelastic scattering reactions (n, n'γ). Since each chemical element has its own characteristic gamma spectrum, it is possible to conduct an elemental analysis of the object under study.
Irradiation of the material on the conveyor occurs by a beam of fast tagged neutrons with an energy of 14 MeV from the ING-27 portable neutron generator manufactured by NL Dukhov All-Russian Scientific Research Institute of Automation (VNIIA), gamma quanta from inelastic scattering reactions are recorded by a system of 14 scintillation detectors based on a BGO crystal. Tagged neutron is carried out by registration of α-particles formed in the reaction d+3H →4He+n, which makes it possible to reduce the influence of the background by 200 times. The analyzer also includes power systems, data collection systems and biological protection.
The analyzer provides data on the elemental composition of material on the conveyor every 40-60 seconds. The results of the analyzer operation for control of sinter are discussed.
1. V. Valkovic, «14 MeV Neutrons: Physics and Applications», Taylor & Francis Group, 2016, 516 p.
2. Alexakhin V.Y. et al., «Detection of Diamonds in Kimberlite by the Tagged Neutron Method.», Nuclear Instruments and Methods" A785, 2015, 9 p.
3. V.M. Bystritsky et al., «Physics of Particles and Nuclei Letters», 2008, Volume 5, p.441.

Speaker: Ms Albina Akhunova (Diamant LLC)

Akhunova AI.docx

15:00 → 16:40 Experimental and theoretical studies of nuclear reactions

Convener: Alexander Kuznetsov (Lomonosov Moscow State university, Faculty of Physics; Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University)

15:00 THE SPECIFIC FEATURES OF PHOTODISINTEGRATION OF 58,60Ni

The reliability of experimental cross sections of partial photoneutron reactions (g,1n) and (g,2n) for 58,60Ni obtained using both bremsstrahlung [1-4] and quasimonoenergetic annihilation photons [5] were analyzed using the objective physical criteria. The ratios of partial reaction cross sections to that of neutron yield reaction Fi = CS(g,in)/CS(g,xn) = CS(g,in)/[CS(g,1n) + 2CS(g,2n)] were used. In the cases of (g,1n) and (g,2n) reactions reliable data ratios Fiexp must have values not higher than 1.00 and 0.50 [3] and near the values Fitheor calculated in the combined photonuclear reaction model (CPNRM) [6]. It was obtained that data under discussion [1-4] do not satisfy those criteria. The new reliable cross sections of partial reactions for both 58,60Ni were evaluated using data [5] and experimental-theoretical method [7]: CSeval(g,in) = Fitheor CSexp(g,xn). It was found that the noticeable differences between experimental and evaluated cross sections are because of definite shortcomings of the neutron multiplicity sorting method used [5]. The main reason is that generally the CSexp(g,2n) in reality in a large extent is the CS(g,1n1p). The point is that in the case of 58Ni the threshold B1n1p of the (g,1n1p) reaction is 2.9 MeV smaller in comparison with B2n and the value of CS(g,1n1p) is ~20 times larger in comparison with CS(g,2n). In the case of 60Ni the correspondent deviations are somewhat less but also very large. The role of (g,1n1p) reaction in the cases of relatively light nuclei is very specific. The sharing of investigated nucleus excitation energy between neutron and proton in the (g,1n1p) reaction is (at least could be) similar to that between two neutrons in the reaction (g,2n) and because of that energies of neutrons from both partial reactions could be near. But outgoing neutron from the reaction (g,1n1p) has multiplicity equal to 1 but both neutrons from the reaction (g,2n) have multiplicity equal to 2. Therefore the reaction (g,2n) cross sections for both 58,60Ni were obtained [5] with significant systematic uncertainties and must not be recommended for using in research and applications.

1. K. Min et al., Phys. Rev. Lett. 21, 1200 (1968).
2. D. G. Owen et al., Nucl. Phys. A 140, 523 (1970).
3. B. I. Goryachev et al., JETF Letters 8, 46 (1968).
4. B. I. Goryachev et al., Sov. J. Nucl. Phys. 11, 141 (1970).
5. S. C. Fultz et al., Phys. Rev. 10, 608 (1974).
6. B. S. Ishkhanov et al., Phys. Atom. Nucl. 71, 493 (2008).
7. V. V. Varlamov et al., Bull. Rus. Acad. Sci. Phys. 74, 833 (2010).

Speaker: Prof. Vladimir Varlamov (Lomonosov Moscow Statw University, Skobeltsyn Institute of Nuclear Physics)

Varl_Ni-reliability.docx

15:20 PARTIAL PHOTONUCLEAR REACTION CROSS SECTIONS OBTAINED USING BREMSSTRAHLUNG

Cross sections of partial reactions, primarily (g,1n) and (g,2n, are widely used in both scientific researches and applications. There are two main methods for obtaining those in various experiments. The majority of CS(g,1n) and CS(g,2n) for was obtained using quasimonoenergetic annihilation photons [1,2] in Livermore (USA) and Saclay (France). The method of photoneutron multiplicity sorting using measured neutron energy was used for direct measurement the cross sections CS(g,1n) and CS(g,2n). For 19 nuclei from 51V to 209Bi investigated in both laboratories significant systematic disagreements were found [3,4]. Using the objective physical criteria of data reliability it was shown that in general partial reaction cross sections obtained using the method of neutron multiplicity sorting are not reliable because the presence of significant systematic uncertainties from the unreliable (erroneous) identification of multiplicity of detected neutron [5]. The most important criteria are that positive ratios Fiexp = CS(g,in)/CS(g,xn) = CS(g,in)/[CS(g,1n)+2CS(g,2n)] for reliable data in the cases of (g,1n) and (g,2n) reactions must have values not higher than 1.00 and 0.50 and near the values Fitheor calculated in the combined photonuclear reaction model (CPNRM). Data on partial reaction cross sections were obtained also using bremsstrahlung. The neutron yield cross sections CS(g,xn) = CS(g,1n)+2CS(g,2n) were measured directly and used for determination of CS(g,2n) using the corrections based on the nuclear reaction statistical theory. After that CS(g,1n) was obtained using the correspondent subtraction procedure CS(g,1n) = CS(g,xn)-2CS(g,2n). The reliability of partial reaction cross sections CS(g,1n) and CS(g,2n) for nuclei 59Co, 58,60Ni, 90Zr, 112,114,119Sn, 127I, 165Ho, 166Er, 181Ta was investigated using the criteria mentioned above. It was found that generally those cross sections are not reliable because of many physically forbidden negative values or values for which F2exp > 0.50. This is the results of some shortcomings in GDR statistical theory description of competition between particle reactions.

1. S. S. Dietrich et al., At. Data Nucl. Data Tables 38, 199 (1988).
2. IAEA Nuclear Data Section database, Experimental Nuclear Reaction Data (EXFOR)”, http://www-nds.iaea.org/exfor;
   USA National Nuclear Data Center database, CSISRS and EXFOR Nuclear reaction experimental data”, http://www.nndc.bnl.gov/exfor/exfor00.htm.
   CDFE Nuclear Reaction Database (EXFOR)”, http://cdfe.sinp.msu.ru/exfor/index.php.
3. E. Wolynec et al., Phys.Rev. C 29, 1137 (1984).
4. V. V. Varlamov et al., International Nuclear Data Committee, INDC(CCP)-440, IAEA NDS, Vienna, Austria, 2004, p. 37.
5. V. V. Varlamov et al., Phys. Atom. Nucl., 80, 957 (2017).

Speaker: Prof. Vladimir Varlamov (Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics)

Varl_Stat-theor-corr.docx

15:25 TO YIELD STUDIES FOR THE REACTIONS 13C(gamma, p), 14N(gamma, 2p), 14N(gamma, 2n) WITH (12B, 12N)- ACTIVITY MEASUREMENTS BY DeltaE- DETECTOR TELESCOPES AT THE PULSED ELECTRON ACCELERATOR

Studies of yields for photonuclear reactions with production of 12B((T½) = 20.2 ms) and 12N((T½) = 11.0 ms) are interesting both for development of models of nuclear reactions with nuclei-products near the boundaries of stability to nucleon-emission, and for detection of hidden explosives and drugs (see, e.g., [1]) with (12B and 12N)- activity registration.
In [2, 3], there were considered features of emission of gamma- quanta, electrons and positrons from targets at decays of produced in them (12B and 12N)- nuclei.
In [4] for the reactions 13C(gamma, p), 14N(gamma, 2p), 14N(gamma, 2n), there was given analysis of known experimental and model-calculated data (including our own ones calculated by means of the widely used models of nuclear reactions). It was shown that new yield measurements are necessary for these reactions because estimated discrepancies of data are on the level of 1–2 orders of magnitude. In [5], there were briefly considered variants of such measurements with detecting (12B and 12N)- activities by scintillation gamma- spectrometers or telescopes of thin DeltaE- counters. The first variant with NaI- spectrometers was considered in [6].
In the present work we considered measuring of (12B and 12N)- activities at the pulsed electron accelerator based on registration of emitted from the target electrons or positrons by rather thin telescopic plastic counters with usage of the controlled PMT power supply dividers for all these scintillation counters [7].

1. L.Z. Dzhilavyan. Phys. Part. Nucl. No 5, 556 (2019).
2. S.S. Belyshev et al., Bull. Russ. Acad. Sci.: Phys. 80, P. 566 (2016).
3. S.S. Belyshev et al., Bull. Russ. Acad. Sci.: Phys. 83, P. 449 (2019).
4. O.I. Achakovskiy et al., Bull. Russ. Acad. Sci.: Phys. 80, P. 572 (2016).
5. L.Z. Dzhilavyan. About yield measuring for the reactions 14N(gamma, 2n)12N and 14N(gamma, 2p)12B. Poster Reports of the XIV International Seminar on Electromagnetic Interactions of Nuclei (EMIN – 2015, October 5-8, Moscow, Russia). INR RAS, Moscow, 2016, pp. 12–15.
6. S.S. Belyshev et al., Bull. Russ. Acad. Sci.: Phys. 86, No. 4. P. 577 (2022) (in Russian)
7. L.Z. Dzhilavyan et al., Bull. Russ. Acad. Sci.: Phys. 83, P. 474 (2019).

Speaker: Leonid Dzhilavyan (Institute for Nuclear Research of the Russian Academy of Sciences)

34-nucleus-2022_abstract_34_Belyshev, Dzhilavyan, et al..doc

15:45 PHOTONUCLEAR REACTIONS: SOME POSSIBILITIES FOR METHODOLOGICAL IMPROVEMENT

Cross sections for photonuclear reactions in the energy range of giant dipole resonance have often been measured. One of the most commonly used experimental methods was the activation of a selected material in a high-energy bremsstrahlung beam. Considering that there is still a need for reliable results of cross-sectional measurements of photonuclear reactions, this work will refer to some results aimed at improving the methodology itself.
Insufficiently precise knowledge of the energy spectrum and intensity of the high energy photon beams has lead to the use of comparators, ie. materials of well known activation properties. With a known geometry of bremsstrahlung production, it is possible to obtain a reliable energy distribution of the emitted photon radiation using some simulation routine. In this case, the photon beam can be calibrated by measuring the dose. By the activation of the gold (for which the cross section for (γ,n) reaction is well known) and dosimetry measurements, calibration of photon beams of Microtron 25, in the energy interval from 5 MeV to 25 MeV was performed. Dosimetry measurements were done using calibrated ionization chamber intended for dosimetry control of photon beams of therapeutic linear accelerators.
Reconstruction of cross-sections from photoactivation measurements has so far been performed using different numerical procedures. In reactor physics, powerful computer algorisms have been developed to solve similar problems – to estimate the shape of the energy differential cross section based on neutron activation measurements. It has been shown [1] that a couple of such software packages can be successfully used in photoactiovation measurements, in the energy range up to 10 MeV. In this work, a step further was done and mentioned software codes were tested on the example of gold activation at energies up to 25 MeV.

1. Z. Medić, The European Physical Journal A 57, 258 (2021)

Speaker: Miodrag Krmar (Faculty of Science, University Novi Sad)

photonuclear_Au2.docx

16:05 Photoneutron Cross Sections Of Cobalt

PHOTONEUTRON CROSS SECTIONS OF COBALT

A. V. Druzhinina$^{1}$, S. S. Belyshev$^{1,2}$, V. V. Khankin$^{2}$, A. A. Kuznetsov$^{1,2}$
$^{1}$Lomonosov Moscow State University, Moscow, Russia; $^{2}$Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
E-mail: alexdruzhinina@gmail.com

From measurements of gamma ray activities, induced by irradiating $^{59}$Co with 55 MeV bremsstrahlung, the yields of the reactions (γ,n), (γ,2n), (γ,3n), (γ,2pn) were determined. Absolute yields were obtained by reference to cross section data for the Cu(γ,n) process. The isomeric yield ratio (Ym/Yg) of $^{58}$Co, which was measured at this energy, is 1.255±0.004. This value is in a good agreement with previous experimental data, such as 1.33±0.09 at the maximum beam energy equel 54 MeV [1].
The flux-weighted average cross-sections for the (γ,n), (γ,2n) reactions of $^{59}$Co are 18.53±0.03, 6.99±0.04 mb, respectively. They were compared with the flux-weighted average cross-sections obtained from other experimental data, based on mono-energetic and bremsstrahlung data, and theoretical predictions. These results of current experiment are lower then results, obtained by Alvarez [2] for (γ,n) reaction, and higher for (γ,2n) reaction, which are 22.6 mb and 6.19 mb respectively.
The theoretically simulated $^{59}$Co(γ,n)$^{58}$Co, $^{59}$Co(γ,2n)$^{57}$Co reaction average cross-sections based on TALYS show a general agreement with experimental data (18.58, 6.69 mb respectively).

1. H. Lichblau, A. Goldmann, Z. Phys., 205, No. 1, 47 (1967).
2. R.A. Alvarez, B.L. Berman, Phys. Rev. C, Vol. 20, 1 (1979).

Speaker: Mrs Alexandra Druzhinina (Lomonosov Moscow State university, Faculty of Physics)

nucleus-2022-abstract-Druzhinina.docx

15:00 → 16:40 Intermediate and high energies, heavy ion collisions

Convener: Igor Lokhtin

15:00 Elliptic flow for π⁰ mesons in asymmetric Cu+Au collision system at √s_NN=200 GeV

Quark-gluon plasma (QGP) is a state of nuclear matter, where quarks and gluons are deconfined [1]. It can be formed in laboratory conditions in collisions of heavy ions at high energies [2]. Elliptic flow (v₂), which reflects azimuthal anisotropy of hadron production in heavy ion collisions, is one of the main observables characterizing properties of QGP [3]. The study of the elliptic flow in relativistic heavy ion collisions (Cu+Cu and Au+Au) leads to the assumption that the QGP behaves as a nearly inviscid fluid [4]. The measurements of the v₂ in Cu+Au asymmetric collision system allow to determine the dependence of the elliptic flow for light hadrons on the initial geometry of the system [5]. Since π⁰ meson consists of the first-generation quarks (u, d), its production is well-measurable up to high values of p_T. Thus, the measurement of π⁰ meson v₂ in Cu+Au collisions is considered as an effective tool to study QGP’s properties.
In symmetric collision systems such as Cu+Cu and Au+Au the scaling of elliptic flow values v₂ for π⁰ mesons with the participant nucleon eccentricity (ε₂) and with the third root of the number of participant nucleons (N_part^1/3) in all centrality classes was observed [6]. Such scaling could be interpreted in the frame of relativistic hydrodynamic model, considering QGP formation [7]. The observation of ε₂ N_part^1/3 scaling in asymmetric Cu+Au collision system could lead to a conclusion that v₂/(ε₂ N_part^1/3) values for π⁰ mesons do not depend on the initial geometry of the system. Current report presents the study of the elliptic flow for π⁰ mesons in asymmetric Cu+Au collisions at √s_NN=200 GeV versus transverse momentum and centrality of the collision.
The research is partially funded by the Ministry of Science and Higher Education of the Russian Federation under the strategic academic leadership program ’Priority 2030’ (Agreement 075-15-2021-1333 dated 30.09.2021).
1. H. Buesching et al. (PHENIX Collaboration), J.Phys. G31 (2005) S473-S480;
2. Adcox K. et al. (PHENIX Collaboration), Nucl. Phys. A 2005. V.757;
3. P. Sorensen. (2010). Elliptic Flow: A Study of Space-Momentum Correlations in
Relativistic Nuclear Collisions. Quark-gluon plasma 4 (pp. 323-374);
4. K. Adcox et al. (PHENIX Collaboration), Nucl. Phys. 103 A757, 184 (2005);
5. R. Snellings. New J.Phys., 13 055008 (2011);
6. A. Adare et al. (PHENIX Collaboration), Phys.Rev.C 88, 064910 (2013);
7. Chaudhuri, A. (2013). Viscous Hydrodynamic Model for Relativistic Heavy Ion Collisions. Advances in High Energy Physics. 2013. 10.1155/2013/693180.c

Speaker: Egor Bannikov (Peter the Great St.Petersburg Polytechnic University (SPbPU))

Bannikov_Nucleus2022_final.docx

Nucleus2022_Bannikov_Presentation.pdf

15:20 Femtoscopic analysis of identical charged kaons in Pb–Pb collisions at 5.02 TeV with ALICE

Femtoscopy is an important tool for studying space–time properties of the emission sources created in heavy-ion collisions such as spatial sizes, evolution duration, collective flow effects, etc. The importance of kaon femtoscopy is to check different model scenarios that work equally well for pions. In this contribution, we present the results of femtoscopic analysis of identical charged-kaon correlations in Pb–Pb collisions at 5.02 TeV. The results of one- and three-dimensional analyses show that the kaon femtoscopic radii are smaller for more peripheral collisions and decrease with increasing of transverse momentum. According to hydrokinetic models, it might be explained by the radial expansion of the emission source. Comparison between the obtained three-dimensional radii and the integrated Hydro Kinetic Model calculations for two particularization temperatures obtained from two different Equations of State has been performed. The one-dimensional radii are compared with the same results for other colliding systems, Pb–Pb at 2.76 TeV, p–Pb at 5.02 TeV and pp at 7 TeV, as a function of event multiplicity to check whether they have the common trend or not. Another important result of this analysis is the extraction of the maximal emission times for kaons in a wide centrality range (from 0 to 90%).

Speaker: Mr Gleb Romanenko (JINR, MSU)

nucleus-2022-abstract-Romanenko.docx

15:40 Hadronic resonance production with ALICE at the LHC

The study of resonance production is important in proton-proton, proton-nucleus, and heavy-ion collisions.
In heavy-ion collisions, since the lifetimes of short-lived resonances are comparable with the lifetime
of the late hadronic phase, regeneration and rescattering effects become important and resonance yield ratios
to those of longer lived particles can be used to estimate the time interval between the chemical and kinetic freeze-out.
The measurements in pp and p-Pb collisions constitute a reference for nuclear collisions
and provide information for tuning event generators inspired by Quantum Chromodynamics.
In this talk, recent results on short-lived hadronic resonances obtained with ALICE at LHC energies are presented.
The presented results include system-size and collision-energy evolution of transverse momentum spectra,
yields and the ratios of resonance yields to those of longer lived particles, and nuclear modification factors.
The results will be compared with model predictions and measurements at lower energies.

Speaker: Sergey Kiselev (NRC «Kurchatov Institute» - ITEP, Moscow, Russia)

nucleus-2022-abstract-Kiselev.docx

NUCLEUS2022-Kiselev-v4.pdf

16:00 A SPECIFIC HEAT OF NUCLEAR MEDIUM PROBED BY $K_S^0$ MESONS PRODUCED IN $Au+Au$ COLLISIONS AT RHIC

The data [1] on spectra of $K_S^0$ mesons measured by the STAR Collaboration in Au+Au collisions at various centralities characterized by different multiplicity densities of negative particles were analyzed in the $z$-scaling approach [2,3]. The transverse momentum distributions obtained in the BES-I program at RHIC were accumulated in seven centrality classes from the most central 0-5% to peripheral 60-80% collisions in the rapidity range $|y|<0.5$. These data and the earlier STAR data at $\sqrt {s_{NN}}=$ 62, 130 and 200 GeV allow us a detail study of the energy and centrality dependence of $K_S^0$-meson production in a wide range of $\sqrt {s_{NN}}=$ 7.7–200 GeV.
The scaling function $\psi(z)$ was constructed and the self-similarity of $K_S^0$-meson production was confirmed. It was found that the model parameter $c_{AuAu}$ interpreted as a specific heat of produced medium depends on collision energy. The scaling behavior is consistent with an abrupt decrease of $c_{AuAu}$ from the value of 0.16 at $\sqrt {s_{NN}}=$ 7.7 and 11.5 GeV to about 0.09 at the top RHIC energy. At $\sqrt {s_{NN}}=$39 GeV, a kink in the significant drop of this parameter is observed, as well as an indication of its flattening at higher $\sqrt {s_{NN}}$. The non-trivial dependence of $c_{AuAu}$ on the collision energy obtained from the $z$-scaling of $K_S^0$-meson production shows that the strange probe is much more sensitive to properties of nuclear medium than a non-identified negative hadron [3]. The irregularities in the behavior of the specific heat parameter cAuAu could indicate existence of a phase transition in nuclear matter.

1. J. Adam et al. (STAR Collaboration), Phys. Rev. C 102, 034909 (2020).
2. M. Tokarev et al., Phys. Part. Nucl. 51, 141 (2020).
3. M. Tokarev, A. Kechechyan, I. Zborovský, Nucl. Phys. A 993, 121646 (2020).

Speaker: Prof. Mikhail Tokarev (Join Institute for Nuclear Research)

Tokarev_NUCLEUS'22_abstract.docx

Tokarev_NUCLEUS'22_abstract.pdf

15:00 → 16:40 Neutrino physics and nuclear astrophysics

Convener: Евгений Широков

15:00 Testing of the high-energy $\pi$ and K meson production by the primary cosmic protons and helium nuclei

The primary cosmic particles with very high energies are initiating huge cascades of various secondary particles in the atmosphere. The atmospheric muon spectrum at energies from 100 up to $10^{5}$ GeV is formed in decays of the most energetic $\pi$ and K mesons produced by the primary protons and more heavy nuclei with energies above the threshold and up to $10^{7}$ GeV. The primary nuclei may be regarded as a flux of nucleons. A sophisticated scheme of simulations of the atmospheric vertical muon flux has been elaborated. The partial differential energy spectra of the atmospheric vertical muons in the air shower cascades initiated by primary cosmic nucleons with different fixed energies had been simulated with the help of the program package CORSIKA with statistics of $10^{6}$. The suggested scheme of simulations provides a reasonable accuracy at high energies. The eight most popular hadronic interactions models QGSJET-01, QGSJET-II-03, QGSJET-II-04, DPMJET 2.55, VENUS 4.12, EPOS LHC, SIBYLL 2.1 and SIBYLL 2.3 had been used to estimate these partial spectra. These partial spectra of muons have been convolved with the energy spectrum of the primary nucleons to estimate the atmospheric vertical muon flux. The known calculations of the primary cosmic proton and helium nuclei spectra produced in the supernova remnants had been normalized on the AMS-02 data and tested by PAMELA, ATIC-2, CREAM, ARGO-YBJ, ARGO-YBJ &FWCTA, KASCADE, KASCADE-Grande, Tunka, Ice Cube and Telescope Array TALE data. The energy spectrum of the primary nucleons had been estimated with the help of these spectra. At last, the simulated spectrum of the atmospheric vertical muons had been compared with the rather accurate measurements of the atmospheric vertical muon spectra at energies above 100 GeV (e.g., L3+Cosmic, MACRO, LVD, Ice Cube data). This comparison had demonstrated that all tested models failed to reproduce the atmospheric vertical muon flux correctly. The calculated muon fluxes happened to be below data by factors of 1.5 $\div$ 2. Therefore, all tested models underestimate the production of the most energetic charged $\pi$ and K mesons by the primary cosmic nucleons by the same factors at energies from $10^{2}$ up to $10^{7}$ GeV.

Speaker: Mr Anton Lukyashin (MEPhI/MSU)

Dedenko_Lukyashin-nucleus-2022-abstract.docx

Lukyashin-NUCLEUS-2022-ver4new.pdf

15:20 Baryon-antibaryon Asymmetry in p-p, p-A collisions and String Junction Torus as Baryonium DM

The asymmetry of baryon/antibaryon production has been measured in many proton-proton, pion-proton and electron-proton experiments. In the framework of Quark-Gluon String Model (QGSM) the energy dependence of asymmetry tells us about the value of $\alpha_{SJ}$(0), the intercept of String Junction Regge trajectory. In previous QGSM study, the value of intercept has been estimated as 0.5 < $\alpha_{SJ}$(0) < 0.9. Here, SJ behaviors are accumulated in the model based on topological expansion in order to build a neutral object with zero baryon charge. By the way, QCD mass falling under the event horizon of Black Hole (BH) should be symmetric, or in other words, have no charge information. The baryon junctions are easily combinable with antibaryon ones in hexagons. Topologically, hexagon net can coherently cover only the torus surface. The net on the torus has discrete number of baryon/antibaryon junctions. This is only parameter that marks the mass/energy level of this object. It looks like DM particle, is not it? In high energy collisions at LHC, such pomeron loops are to be produced approximately in 1.2 percent of inelastic events. Furthermore, the torus configurations of matter have been revealed in many bright events in space. As an example, Chandra experiment has detected such dense "doughnut" near the event horizon of Super Massive Black Hole (SMBH), which X-ray radiation is screened on 40 percent's. This topological symmetry model of DM seems rather realistic and can help us to deal with an "arm wrestling" between the stiffness of toroid structure of QCD matter and the pressure of gravitational singularity at extremely heavy masses. On the other hand, the instabilities in structure of matter in SMBHs can cause the bursts of giant relativistic hadron jets with the masses of order the own BH mass.

Speaker: Olga Piskunova (P.N.Lebedev Physics Institute of RAS)

BaryoniumDMforNUCLEUS22Piskounova.pdf

15:40 ON THE POSSIBILITY OF USING THE QUANTUM-FIELD APPROACH TO MODELING THE INTERACTION OF MATTER WITH NEUTRINOS TO STUDY THEIR ROLE IN ASTROPHYSICAL PROCESSES

strong text

Speaker: Yury М. Pismak (Department of High Energy and Elementary Particle Physics, State University of Saint-Petersburg,)

Pismak_13_07_22_Nucleus_2022.pdf

16:00 A modified quasiparticle model in the expansion of early universe of quark gluon plasma

A modified quasiparticle model approach is used in the expansion of early universe of quark gluon plasma. We also used Friedmann equation to determine the precise time evolution of the thermodynamic parameters in the early universe of quark gluon plasma (QGP). The output for time variation of the energy density and the time evolution of temperature using finite value of thermal dependent quark mass have plotted. The results show the time evolution of the early universe which also helps in the calculations of other thermodynamic variables like energy density, pressure, entropy etc. This provides deep understanding for the evolution of early universe of quark gluon plasma.

Speaker: Yogesh Kumar (Deshbandhu College, University of Delhi, Kalkaji, New Delhi)

73-nucleus-2022-abstract-earlyuniverse.docx

16:20 DETERMINATION OF PARAMETERS OF THE MODEL WITH THREE STERILE NEUTRINOS ON THE BASE OF EXPERIMENT BEST RESULTS

It is carried out evaluations of parameters values for the model with three active and three sterile neutrinos [1], namely, mixing parameters between active and sterile neutrinos and sterile neutrinos masses. When doing that, results of the BEST experiment (Baksan Experiment on Sterile Transitions) are used [2]. The BEST experiment intends to verification of the gallium anomaly at short distances, that is the deficit of electron neutrinos from radioactive sources. Besides it is taken into account experimental results concerning verification of accelerator [3] and reactor [4, 5] neutrino anomalies at short distances, as well some astrophysical data [6, 7].

1. V.V. Khruschov and S.V. Fomichev // Universe 8, 97 (2022).
2. V.V. Barinov et al. // arXiv: 2201.07364, PP. 1-25 (2022).
3. A.A. Aguilar-Arevalo et al. // Phys. Rev. D 103, 052002 (2021).
4. I. Alekseev et al. // Phys. Lett. B 787, 56 (2018).
5. A.P. Serebrov et al. // Phys. Rev. D 104, 032003 (2021).
6. A. Schneider // Phys. Rev. D 98, 063021 (2018).
7. A. Boyarsky et al. // Prog. Part. Nucl. Phys. 104, 1 (2019).

Speaker: Dr Viacheslav Khruschov (Kurchatov Institute)

Khruschov_Fomichev_Nucleous2022.docx

15:00 → 16:40 Synchrotron and neutron radiation sources and their use in scientific and applied fields

Convener: A Shemukhin (Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia)

15:00 Studying neutron spectrum of photoneutron source of INR RAS

A W-Be-photoneutron neutron source IN-LUE based on a linear electron accelerator was created and installed at the Institute for Nuclear Research of RAS [1]. The shape of the neutron spectrum and flux estimation was obtained earlier as a result of simulation [2]. Due to the impossibility of measuring the neutron spectrum in a wide range of energies within the source, various methods of spectrum unfolding based on the solution of the inverse problem are usually used.
In this work, the results of unfolding the neutron spectrum into photoneutron source chamber of the source are presented. As experimental data for unfolding, we used the data of neutron activation analysis of samples irradiated in the source (Ag, Mg, Mn,Sb, Ti, etc.). To unfold the spectrum, a number of well-known Nuclear Energy Agency (NEA) programs were used [3], which implement various algorithms for solving the inverse problem.
This work also presents the results of measurements of the neutron flux by various methods, as well as their comparison.

1. A.V.Andreev et al. // Bull. Russ. Acad. Sci.: Phys., 2017, V. 81, P. 748.
2. N.Sobolevsky // Fifth Int. Conf. on Nucl. Fragm. (NUFRA2015). Kemer. Oct. 2015.
3. OECD Nuclear Energy Agency (NEA) Data Bank. Computer program services.

Speaker: Alexey Afonin (INR RAS)

210-Afonin_nucleus-2022-abstract.docx

15:20 SYLA – RUSSIAN 4TH GENERATION SYNCHROTRON

For more than 40 years synchrotron-based x-ray sources as well as free-electron lasers based on linear accelerators have been widely used in materials science, spectroscopy, crystallography, research of fast processes, medicine, molecular biology and biochemistry, medicine, and other applied and scientific tasks. Nowadays state-of-art technologies make it possible to design and develop specialized synchrotron that is especially aimed to generate SR by means of insertion devises, such as ondulators or wigglers. Such specialized circular electron accelerators have been called SR sources of the 4th generation. Currently, there are already several operating [1-3] and a number of such specialized SR sources are under design [4-6]. A number of 3rd generation light sources are under modernization up to 4th generation nowdaus. In order to advance the development of the research infrastructure of the Russian Federation, by Decree of the President of the Russian Federation No. 356 of 25.06.2019, a storage synchrotron (the 4th generation SR source) with an energy of 6 GeV and an equilibrium value of the horizontal emittance of the electron beam of no more than 70 pm∙rad (SYLA, former USSR4) is being developed on the basis of NRC KI [7,8]. This paper presents the results of the development of the machine lattice as well as top-up linac injector.

1. MAX IV Facility Detailed Design Report / https://www.maxiv.lu.se/
2. EBS Storage Ring Technical Report / https://www.esrf.eu/
3. L. Liu, R. T. Neuenschwander and A. R. D. Rodrigues, Synchrotron radiation sources in Brazil / .Phil. Trans. R. Soc. A 377: 20180235 (2019).
4. I. Agapov et al. PETRA IV: the ultralow-emittance source project at DESY / J. Synchrotron Rad. (2018). 25, 1277–1290.
5. M. Borland et al., Hybrid seven-bend-achromat lattice for the Advanced Photon Source Upgrade / Proceedings of 2015 IPAC, pp. 1776–1779.
6. HEPS Xu G., Cui X.H., Duan Z., Guo. Y.Y. / Proceedings of International particle accelerator conference. – Denmark, 2017 – P. 2697 – 2699.
7. S. Liuzzo et al., USSR HMBA Storage Ring Lattice Options // 12th IPAC, May 2021, Online, Brazil. TUPAB049.
8. L. Hoummi et al., Optimization and Error Studies for the USSR HMBA Lattice // 12th IPAC, May 2021, Online, Brazil. MOPAB224.

Speaker: Vyacheslav Dyubkov (NRNU MEPhI, NRC KI)

nucleus-2022-abstract-template.docx