热核次级衰变过程对费米能区重离子碰撞核反应产物的影响

The Influence on Sequential Decay of Hot Nuclei at the Final Fragmentation of Heavy-Ion Collision near Fermi Energy

费米能区重离子核反应是研究核物质性质的重要手段,而提取反应中产生碎片的粒子多重性成为连接实验测量和理论模拟的重要纽带之一。然而,实验测量的重离子核反应碎片属于终态分布,而动力学理论模拟的重离子核反应碎片尚具有较大的激发能,可能会因为次级衰变而影响核反应最终碎片的分布。使用反对称化分子动力学模型(AMD)模拟了 40AMe V^(64)Zn+^(112)Sn 反应系统的动力学过程,使用统计衰变模型 GEMINI 模拟热核退激发过程。并采用相同的技术提取两种情况下粒子多重性进行对比分析,结果显示,费米能区重离子核反应碎片的粒子多重性终态分布可能与初级动力学碎片分布存在显著差异。

The heavy-ion collision near the Fermi region is an important tool to reveal the physical properties of nuclear matter and extracting the fragment’s multiplicity has become a powerful indicator between experimental measurement and theoretical modeling. However, the fragments in the experimental measurement belong to the final ground state, while the fragments in theoretical modeling still have large excitation energy after the dynamic process, which may affect the final distribution of fragments due to the sequential decay process. In this study, an Antisymmetric Molecular Dynamics (AMD) model was used to simulate the dynamical evolution of the 40 AMe V^(60)Zn +^(112)Sn reaction system, and a statistical decay model GEMINI was used to simulate the de-excitation process of hot nuclei. The result shows that the fragment multiplicity distribution in the final ground state may be significantly different from that of the primary fragment multiplicity distribution in theoretical dynamics modeling.