Study of the Nuclear Matter Symmetry Energy in the Simulated 140 AMeV ^58,64Ni+⁹Be Reactions by Isoscaling Method

We have simulated the reactions 140 AMeV ^58,64Ni+⁹Be by antisymmetric molecular dynamics model (AMD) and studied the evolution of △μ_n(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.