Mechanism of ternary breakup in the reaction Au 197 + Au 197 at 15 A MeV
Mechanism of ternary breakup in the reaction Au 197 + Au 197 at 15 A MeV
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DOI：
10.1103/physrevc.82.054608
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发表时间：
2010-11
影响因子：
3.1
通讯作者：
Junlong Tian;Xi-zhen Wu;Zhu-xia Li;K. Zhao;Y. Zhang;Xian Li;S. Yan
中科院分区：
文献类型：
--
作者：
Junlong Tian;Xi-zhen Wu;Zhu-xia Li;K. Zhao;Y. Zhang;Xian Li;S. Yan
利用改进的量子分子动力学模型研究了能量为 $15A$ MeV 的重系统 $^{197}\mathrm{Au}+^{197}\mathrm{Au}$ 三元破裂的机制。计算结果再现了一系列实验探索的三元破裂事件的特征；即，三个碎片的质量在大小上相当，并且碰撞系统的非常快速、几乎共线的破裂在三元破裂事件中占主导地位。此外，还研究了不同三元反应模式的时间尺度演变以及具有冲击参数的三个碎片的质量分布行为。还研究了复合反应系统构型的时间演化。我们发现，对于具有实验中发现的特征的大多数三元破裂事件，复合材料系统的构型具有双预制颈形状。研究表明，那些具有实验中发现的特征的三元破裂事件发生在相对较小的冲击参数反应中，而不是发生在外围反应中。外围反应处的三元分解反应属于颈部发射的二元分解反应。
The mechanism of the ternary breakup of the very heavy system $^{197}\mathrm{Au}+^{197}\mathrm{Au}$ at an energy of $15A$ MeV has been studied by using the improved quantum molecular dynamics model. The calculation results reproduce the characteristic features in ternary breakup events explored in a series of experiments; i.e., the masses of three fragments are comparable in size and the very fast, nearly collinear breakup of the colliding system is dominant in the ternary breakup events. Further, the evolution of the time scales of different ternary reaction modes and the behavior of mass distributions of three fragments with impact parameters are studied. The time evolution of the configurations of the composite reaction systems is also studied. We find that for most of the ternary breakup events with the features found in the experiments, the configuration of the composite system has two-preformed-neck shape. The study shows that those ternary breakup events having the characteristic features found in the experiments happen at relatively small impact parameter reactions, but not at peripheral reactions. The ternary breakup reaction at peripheral reactions belongs to binary breakup with a neck emission.