Mass dependence of onset of multifragmentation in low energy heavy-ion collisions

Abstract

Based on the quantum molecular dynamics (QMD) picture, we calculate the energy and mass dependence of fragment production. For the present study, we simulated the reactions of ${}^{20}Ne{+}^{20}Ne$, ${}^{40}Ar{+}^{45}Sc$, ${}^{58}Ni{+}^{58}Ni$, ${}^{86}Kr{+}^{93}Nb$,${}^{129}Xe{+}^{124}Sn$ and ${}^{197}Au{+}^{197}Au$ at central geometry. Our findings clearly show a linear mass dependence for the peak center-of-mass energy at which the maximal IMF production occurs. Such linear dependence for peak center-of-mass energy on the system size has also been observed in recent experimental studies. We also predict a similar behavior for the multiplicities of different kinds of fragments. Experiments are called for to verify this prediction.