Microscopic study of neutron-induced fission process of^(239)Pu via zero-and finite-temperature density functional theory  

作　　者：陈永静 宿阳 刘丽乐 董国香 葛智刚 舒能川 王小保 Yong-Jing Chen;Yang Su;Li-Le Liu;Guoxiang Dong;Zhigang Ge;Nengchuan;Xiaobao Wang(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》2023年第5期178-187,共10页中国物理C（英文版）

基　　金：Supported by the National Natural Science Foundation of China(11790325,12275081,11790320,11790321,11961131010,11605054,12105369,12147219,12047568);the Continuous Basic Scientific Research Project(WDJC-2019-09)。

摘　　要：To study the neutron-induced fission of^(239)Pu,potential energy surface(PES)calculations were performed using zero and finite-temperature density functional theory(FT-DFT)with the Skyrme force.The energy of the incident neutron was simulated by the temperature of the FT-DFT.The variations of the least-energy fission path,fission barrier,total kinetic energy,scission line,and mass distribution of fission fragments with the incident neutron energy were analyzed.It was learned that an increase in the temperature lowers the barrier height,the isomericstate energy,and the ridge between symmetric and asymmetric fission valleys.Additionally,the gaps of the single particle levels become smaller with an increase in the temperature.As the temperature increases,the pre-fission region shrinks,and the scission occurs at smaller deformation around the symmetric fission channel.At low temperatures,the pairing correlations in the collective space are similar to those in zero-temperature DFT,and when the temperature is T>0.3 MeV,the pairing gaps decrease rapidly.Two different methods were used to calculate the fission yields of the neutron-induced fision^(239)Pu(n,)with different incident neutron energies,in the framework of timedependent generator coordinate method(TDGCM).One way to calculate the fission yield of^(239)Pu(n,f)is to solve the collective equation of the TDGCM by using the PES from the FT-DFT with the corresponding temperature.The other involves using the PES from the zero-temperature DFT and adjusting the initial collective energy of the wave packet in the TDGCM according to the incident neutron energy.For the cases of the lower incident neutron energies,these two methods gave similar results and reproduced the experimental peak and width of fission fragment distribution.However,for the highest incident neutron energy considered in this study,the results from the TDGCM using the PES from zero-temperature DFT deviated explicitly from the experimental data,whereas those obtained by using the PES from FT-DFT remained

关 键 词：nuclear fission density functional theory potential energy surfaces fission fragment distribution 

分 类 号：O571.43[理学—粒子物理与原子核物理]