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 mi...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.展开更多
基金Supported by National Natural Science Foundation of China(60807036,10774154,11074265,10804060)the "Chenguang" Program of Shanghai Educational Development Foundation of China(2007CG57)+1 种基金the Science and Technology Commission of Shanghai Municipality (10ZR1422300)Shanghai Municipal Education Commission(11YZ83)
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)
文摘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.
