1School of Information Engineering, Hangzhou Dianzi University, Hangzhou 310018 2School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 3Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000
Symmetry Energy Effects in a Statistical Multifragmentation Model
1School of Information Engineering, Hangzhou Dianzi University, Hangzhou 310018 2School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 3Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000
摘要The symmetry energy effects on the nuclear disintegration mechanisms of the neutron-rich system (A0=200, Z0=78) are studied in the framework of the statistical multifragmentation model (SMM) within its micro-canonical ensemble. A modified symmetry energy term with consideration of the volume and surface asymmetry is adopted instead of the original invariable value in the standard SMM model. The results indicate that as the volume and surface asymmetries are considered, the neutron-rich system translates to a fission-like process from evaporation earlier than the original standard SMM model at lower excitation energies, and its mass distribution has larger probabilities in the medium-heavy nuclei range so that the system breaks up more averagely. When the excitation energy becomes higher, the volume and surface asymmetry lead to a smaller average multiplicity.
Abstract：The symmetry energy effects on the nuclear disintegration mechanisms of the neutron-rich system (A0=200, Z0=78) are studied in the framework of the statistical multifragmentation model (SMM) within its micro-canonical ensemble. A modified symmetry energy term with consideration of the volume and surface asymmetry is adopted instead of the original invariable value in the standard SMM model. The results indicate that as the volume and surface asymmetries are considered, the neutron-rich system translates to a fission-like process from evaporation earlier than the original standard SMM model at lower excitation energies, and its mass distribution has larger probabilities in the medium-heavy nuclei range so that the system breaks up more averagely. When the excitation energy becomes higher, the volume and surface asymmetry lead to a smaller average multiplicity.
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2011, Vol. 28 
