Isospin dependence of nuclear multifragmentation in statistical model  

作　　者：张蕾 谢东珠 张艳萍 高远 

机构地区：[1]School of Information Engineering, Hangzhou Dianzi University [2]College of Mathematics and Sciences, Shanghai Normal University [3]Department of Nuclear Physics, China Institute of Atomic Energy

出　　处：《Chinese Physics C》2011年第6期567-571,共5页中国物理C（英文版）

基　　金：Supported by Natural Science Foundation of China (10975064, 10905041, 11005171);General Programs of Social Science Research Fund of Ministry of Education of China (10YJAZH137)

摘　　要：The evolution of nuclear disintegration mechanisms with increasing excitation energy, from compound nucleus to multifragmentation, has been studied by using the Statistical Multifragmentation Model （SMM） within a micro-canonical ensemble. We discuss the observable characteristics as functions of excitation energy in multifragmentation, concentrating on the isospin dependence of the model in its decaying mechanism and break-up fragment configuration by comparing the A0 = 200, Z0 = 78 and A0 = 200, Z0 = 100 systems. The calculations indicate that the neutron-rich system （Z0 = 78） translates to a fission-like process from evaporation later than the symmetric nucleus at a lower excitation energy, but gets a larger average multiplicity as the excitation energy increases above 1.0 MeV/u.The evolution of nuclear disintegration mechanisms with increasing excitation energy, from compound nucleus to multifragmentation, has been studied by using the Statistical Multifragmentation Model （SMM） within a micro-canonical ensemble. We discuss the observable characteristics as functions of excitation energy in multifragmentation, concentrating on the isospin dependence of the model in its decaying mechanism and break-up fragment configuration by comparing the A0 = 200, Z0 = 78 and A0 = 200, Z0 = 100 systems. The calculations indicate that the neutron-rich system （Z0 = 78） translates to a fission-like process from evaporation later than the symmetric nucleus at a lower excitation energy, but gets a larger average multiplicity as the excitation energy increases above 1.0 MeV/u.

关 键 词：statistical model MULTIFRAGMENTATION microcanonical ensemble isospin dependence 

分 类 号：O571.4[理学—粒子物理与原子核物理] TV698.11[理学—物理]