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Recently, there has been increased interest in experimental studies on the production of new isotopes in multinucleon transfer reactions [1,2]. Reactions on 48Ca ion beams are successfully used for the synthesis of new nuclei in a wide range of masses and charges. In particular, it is of interest to obtain new isotopes with the number of neutrons N = 126 in the reaction channels of multinucleon transfers [3]. To estimate the cross sections for the formation of nuclei in these reactions, we conducted an experiment on their detection. In the experiment, nuclei with masses greater than the target mass values were measured.
The experiment was carried out on a 48Ca (5,8 MeV/nucleon) ion beam using 197Au (6 µm thick) and 238U (1 µm thick) targets. Specially prepared targets were irradiated on a beam of accelerated ions, on a cyclotron U-400 at the FLNR JINR. The activation method was used to identify the nuclei formed in the reactions. Measurement of induced activity (gamma and alpha) was carried out in the “off-linе” mode.
In the reaction of 48Ca+Au, neutron pickup channels for 1n and 3n were measured. The cross sections of these channels were σ (+1n) - 150 mb and σ (+3n) – 0.5 mb, respectively. The GRAZING [4] code used to analyze the obtained values gives a good agreement with the experimental results.
In the 48Ca+Au reaction induced alpha activity of 206Po nuclei was observed, which corresponds to the transmission channel (+5p+9n) from the projectile nucleus to the target nucleus.
The 48Ca+U reaction products were measured using an alpha spectrometer. Among the products, the nuclei 228Th, 239Am, 255Fm were identified by the measured half-lives and characteristic energies of alpha particles. These products correspond to the following channels 238U(-2p-8n) → 228Th, 238U(+3p-2n) → 239Am, 238U(+8p-+9n) → 255Fm. The value of the section of these channels σ(228Th) ~ 55 μb, σ(239Am) ~ 1.2 μb, σ(255Fm) ~ 2.2 μb.
Thus, the cross section data show that such reactions are suitable for obtaining nuclei of multinucleon transfers. Further analysis of the obtained data is underway.
| The speaker is a student or young scientist | Yes |
|---|---|
| Section | 2. Experimental and theoretical studies of nuclear reactions |
