Rate of Excited-Nucleus Fissionwithin a Multidimensional Stochastic Approach

摘要

A stochastic approach to describing the dynamics of the nuclear-fission process is applied tostudy the effect of the number of dimensions on the fission rate within the dynamical model used. The timedependence of the fission rate is calculated on the basis of a multidimensional Langevin equation withouttaking into account particle evaporation. The one-, two-, and three-dimensional cases are considered forthe example of the {c, h, a} parametrization of nuclear-surface shapes. The calculations are performed for a large number of compound nuclei whose parameter Z2/A falls within the range 20 < Z2/A < 40. Thestationary level of the fission rate is found to increase considerably upon going over from the one- to thethree-dimensional case. This increase is especially pronounced for light fissile nuclei in the vicinity of theBusinaro—Gallone point. Also, the stationary fission-rate level obtained from our dynamical simulation iscompared with its counterpart calculated by the Kramers formula generalized to the multidimensional case.