Role of shell effects on producing neutron-rich nuclei in the region via multinucleon transfer reactions
F.C. Dai (State Key Laboratory of Heavy Ion Science and Technology, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China)
; P.W. Wen (China Institute of Atomic Energy, Beijing, 102413, China); C.J. Lin (China Institute of Atomic Energy, Beijing, 102413, China, College of Physics and Technology, Guangxi Normal University, Guilin, 541004, China); J.J. Liu (State Key Laboratory of Heavy Ion Science and Technology, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China); X.X. Xu (University of Chinese Academy of Sciences, Beijing, 100049, China, State Key Laboratory of Heavy Ion Science and Technology, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China, Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, 516003, China); et al - Show all 8 authors
Neutron-rich nuclei near the shell closure are vital for r-process nucleosynthesis but remain challenging to produce. Multinucleon transfer reactions offer a promising route. We investigate the role of shell effects in such processes by extending the CLIM-H model with a deformation-dependent mass formula and a scaling factor a that linearly adjusts the shell-correction strength. Calculations for 136Xe on 208Pb, 204Hg, and 208Hg targets reveal a dual role: shell effects enhance few-nucleon transfers near the entrance channel but strongly suppress fragments requiring the transfer of many nucleons, most severely for the doubly magic 208Pb. This suppression stems from the cumulative transfer probabilities and is aggravated by lower survival after deexcitation. Thus, optimal production of exotic nuclei requires avoiding strongly shell-closed collision partners at , as exemplified by doubly magic 208Pb. We propose 238U + 204Hg at E c.m. ≃ 1.45 VB as a superior system, predicting significantly enhanced yields.
