Effect of dissipation coefficient of the K coordinate in dynamical modeling of nuclear fission of 178W produced in fusion reaction

Abstract

In this paper, a stochastic approach based on two-dimensional dynamical model was used to simulate the fission process of the excited compound nucleus [Formula: see text]W produced in [Formula: see text] reaction. In the dynamical calculations, the elongation parameter of the nucleus was used as the first dimension and the projection of the total spin of the compound nucleus onto the symmetry axis, [Formula: see text], considered as the second dimension. The average pre-fission multiplicities of neutron, light charged particles and the total kinetic energy of the fission fragments were calculated for [Formula: see text]W and the results of calculations compared with the experimental data over a wide range of excitation energy. In the dynamical calculations, dissipation was generated through the chaos weighted wall and window friction formula and the dissipation coefficient of [Formula: see text], was considered as a free parameter and its magnitude inferred by fitting measured data on the average pre-fission multiplicities of neutron and proton for the compound nucleus [Formula: see text]W. It was shown that the results of calculations are in good agreement with the experimental data by using the dissipation coefficient of [Formula: see text] in the range [Formula: see text]. It was also shown that the results of calculations with [Formula: see text] provide a better agreement with the experimental data than with a deformation-dependent dissipation coefficient. Furthermore, it was also shown that differences between the results of calculations for the total kinetic energy of the fission fragments calculated by using different values of dissipation coefficient of [Formula: see text] are small.