Model for particle emission from a fissioning system

Abstract

The differential emission probability for a neutron emitted in a binary fission process due to nonadiabatic effects in the coupling of the single-particle degrees of freedom to the accelerated relative motion of the fragments is investigated within a model which represents each nucleus by a nondeformed one-term separable potential. Initially the neutron is bound in a two-center eigenstate, referring to a certain separation distance of the centers of the potentials. The collective relative motion is assumed to proceed with zero angular momentum along a trajectory which is calculated from classical equations of motion including conservative and phenomenological frictional forces. The derivation of measurable quantities from the asymptotic solution of the time-dependent Schr\"odinger equation for the single particle wave function is carefully examined. Numerical calculations have been performed for parameter values which simulate $^{252}\mathrm{Cf}$(sf). The calculated energy spectra and angular distributions of the emitted particles are presented for different values of the mass asymmetry.