Study of fission time and prescission neutron multiplicity using four-dimensional Langevin equations

In this paper, four-dimensional stochastic approach is applied on dynamics of fission process to calculate mean fission time and prescission neutron multiplicity. Elongation, neck thickness, mass asymmetry and orientation degree of freedom (K-coordinate) are four dimensions in dynamical calculations. In order to investigate the influence of the dissipation coefficient of K-coordinate, the stochastic dynamics of the orientation degree of freedom using nonconstant dissipation coefficient was studied. Calculations were done for the ¹⁶O+²⁰⁸Pb and ¹⁶O+²³²Th reactions. Obtained results were compared with a constant dissipation coefficient (γ_K = 0.077(MeVzs)^-1/2). The mean fission time and prescission neutron multiplicity for nonconstant dissipation case were lower than for the constant one. (author)