140 A MeV 58,64 Ni+ 9 Be反应中同位旋标度规律的研究

利用反对称化的分子动力学（AMD）模型模拟140 AMeV 58，64Ni+9Be反应，并利用同位旋标度法研究两相似反应系统的△μn（p）/T随时间演化趋势。分析比较不同碰撞参数和不同反应系统间的△μn（p）/T随时间演化结果，结果表明碰撞参数对重核的对称能影响大，系统不对称度越大对对称能的影响越大，为间接研究激发核体系对称能系数的能量依赖提供了帮助。 We have simulated the reactions 140 AMeV 58,64Ni+9Be by antisymmetric molecular dynamics model (AMD) and studied the evolution of △μn(p)/T with collision time from 20 fm/c to 1 000 fm/c. To study nuclear symmetry energy influencing factors, a comparative analysis has been proceed among theses results with different impact parameters and the difference reactions system. The results show that the impact parameters have a great influence on the symmetry energy of the heavy nucleus, and the greater the asymmerty degree of the system, the greater the influence on the symmetry energy. These results are helpful for the indirect study of the energy dependence of the symmetry energy coefficient of the excited nuclear system.