Influence of the neck parameter on the fission dynamics within the two-center shell model parametrization  

作　　者：Li-Le Liu Xi-Zhen Wu Yong-Jing Chen Cai-Wan Shen Zhu-Xia Li Zhi-Gang Ge Neng-Chuan Shu 刘丽乐;吴锡真;陈永静;沈彩万;李祝霞;葛智刚;舒能川(China Nuclear Data Center,China Institute of Atomic Energy,Beijing 102413,China;School of Science,Huzhou University,Huzhou 313000,China)

机构地区：[1]China Nuclear Data Center,China Institute of Atomic Energy,Beijing 102413,China [2]School of Science,Huzhou University,Huzhou 313000,China

出　　处：《Chinese Physics C》2022年第12期217-225,共9页中国物理C（英文版）

基　　金：Supported by the National Natural Science Foundation of China(12105369,11790324,11790325,11790323,11790320);the Continuous Basic Scientific Research Project(WDJC-2019-09)。

摘　　要：The influence of the neck parameter on the fission dynamics at low excitation energy is studied based on the three-dimensional Langevin approach,in which the nuclear shape is described with the two-center shell model(TCSM)parametrization,and the elongation,mass asymmetry,and fragment deformation are set to be the generalized coordinates of the Langevin equation.We first study the influence of the neck parameter on the scission configuration.We find that there is almost no obvious correlation between the neck parameter and mass asymmetryηat the scission point,indicating that has no evident impact on the fragment mass distribution.The elongation Z_(0)=R_(0) and its correlation with the mass asymmetryηat the scission point are clearly influenced by the neck parameter,which has a strong effect on the total kinetic energy(TKE)distribution of the fragments.The pre-neutron emission fragment mass distributions for 14 MeV n+^(233;235;238)U and^(239)Pu are calculated,and then,based on these results,the post-neutron emission fragment mass distributions are obtained by using the experimental data of prompt neutron emission.The calculated post-neutron emission fragment mass distributions can reproduce the experimental data well.The TKE distributions for 14 MeV n+^(235)U fission are calculated for ε=0.25,0.35,and 0.45,and the results show that the TKE distribution cannot be described very well for the three cases.However,the trend of the calculated TKE distribution withεis just as expected from the scission configuration calculations.The results with ε=0.35 present a better agreement with the experiment data compared with the other two cases.

关 键 词：nuclear fission two-center shell model fragment mass distribution scission configuration 

分 类 号：O571.43[理学—粒子物理与原子核物理]