Speaker
Description
There are numerous ways to treat theoretically nuclear fission, ranging from pure phenomenology, macro-micro method to purely microscopic ones. In this talk, we will concentrate on a macro-micro method in terms of the Langevin equations. In this method, time-evolution of the positions and momenta of shape degree of freedom is treated as a coupled first-order stochastic differential equations including the random force. Since this approach includes the stochastic part, it is able to describe “distribution” or “fluctuation” of observables such as fragment mass, TKE, deformation and correlations of any combination of them can be addressed. Most of the cases, 3-dimensional version is employed for the sake of reducing computational time. In Tokyo Tech., we have developed a 4-dimensinal Langevin method to handle the nuclear fission, and it has be quite power to elucidate mysteries of nuclear fission phenomena. In this presentation, we will introduce our resent development of this approach, considering the 5th parameter as a variational degree-of-freedom to improve the shortcomings of the 4D Langevin method we have encountered so far.