Dynamical Modes And Mechanisms In Ternary Reaction Of Au-197+Au-197

The modes of ternary reaction of Au-127+Au-127 at an energy of 15A MeV are dynamically studied by the improved quantum molecular dynamics model. Three kinds of modes are found by the time evolution of the configurations of the composite reaction systems: One is the direct mode for which the two time separations of the system happen almost simultaneously. Another is the cascade mode for which a two-step process is clearly shown. The third is oblate mode, a kind of very rare fission event. In this case the composite system deforms to a triangle-like configuration with three necks, and then it forms three equally sized fragments along space-symmetric directions in the reaction plane.