Au+Au和Ar+Au快三裂变反应的微观输运理论研究

"快三裂变"是最近实验报道的一种全新核反应现象，特征是高三分裂几率、短分裂时间、三个大碎块分布接近共线。目前实验和理论对这种新反应类型的物理机制尚不清楚，使它成为核反应领域一个富于挑战性又亟需解决的课题。对这一实验现象进行系统的理论研究，必将极大的丰富人们对核反应过程的认识。我们拟采用改进的量子分子动力学(ImQMD)模型，对197Au+197Au和40Ar+197Au的快三裂变反应进行研究：探索快三裂变反应的动力学机制，澄清快三裂变反应的能量耗散机制，研究对称能的密度依赖形式对快三裂变反应动力学过程的影响。通过本项目的研究，希望能阐明产生这种新机制的物理本质和原因，进而给出核反应过程中发生快三裂变事件的最佳反应条件，与国内实验组密切配合，为进一步的实验研究提供重要参考并获取对称能密度依赖信息。

Recently,"fast ternary fission" phenomenon is reported from experiment as a new type of nuclear reaction mechanism. Its features are non-equilibrium fission with the high ternary fission probability, the short time-scale, and near collinear orientation. It becomes a challenging problem that needs to be solved urgently, since the physical mechanism of the fast ternary fission has not yet been well understood in experiment and theory at present.The systematic study of fast ternary fission will greatly enrich people's knowledge about the nuclear reaction process. In this project, the fast ternary fission reaction of 197Au+197Au and 40Ar+197Au will be investigated by using the improved quantum molecular dynamics (ImQMD) model. The contents of this project includes three aspects: 1) To explore the dynamical mechanism of the fast ternary fission reaction; 2) To study the energy dissipation mechanism of the fast ternary fission reaction; 3) To probe the effect of the density dependence of symmetry energy on the dynamical process of the fast ternary fission reaction. Through this research project, we expect to clarify the physical nature of fast ternary fission reaction and to obtain the optimized combination of projectile and target, incident energy and impact parameter for producing the fast ternary fission reaction. We will work together with domestic experimental group and provide more useful information for further experimental study on fast ternary fission.