Production cross sections of new neutron-rich isotopes with Z=92-106 in the multinucleon transfer reaction 197Au+232Th

The multinucleon transfer reactions 197Au + 232Th, 186W + 232Th, and 238U + 232Th are investigated within the framework of dinuclear system (DNS) model with a decay model GEMINI++. The calculated isotopic production cross sections in the 136Xe + 249Cf reaction at Ec.m. = 567 MeV can reproduce the experimental data well. Due to the subshell closures, the behavior of "inverse" quasifission process is found in the collisions of 186W + 232Th and 197Au + 232Th. The reaction 197Au + 232Th is more advantageous to produce neutron-rich isotopes with Z = 92-106 than 186W + 232Th and 238U + 232Th, because it has the lowest value of the potential energy that needed to overcome in the nucleon transfer process. Furthermore, the incident energy dependence of isotopic production cross sections in the reaction 197Au+232Th is studied. It is found that Ec.m. = 756.47 MeV is more suitable for producing new isotopes with Z = 92-98, while Ec.m. = 690.69 MeV is the optimal incident energy for Z = 99-106. The effect of incident energy on the interaction time is also investigated. The production cross sections of 88 unknown neutron-rich transuranium nuclei are predicted with the cross sections at the order of 10-6 to 10 mu b.