Dynamic single-particle effects in fission

Publisher Website
Google Scholar
Abstract
We calculate for a model nucleus the single-particle excitations in the transition from the saddle point to the scission point in the fission process. The model nucleus consists of a square well potential of finite depth filled with noninteracting "protons" and "neutrons." At every stage of the transition between the saddle point and scission point the shape of the potential surface is equal to the surface of the fissioning nucleus as predicted by the liquid-drop model but the depth of the potential is held constant. The rate of change of the nuclear surface is assumed to be equal to that predicted by the dynamical liquid-drop-model calculations of Nix. It is found that for this time scale there is a small probability for the particles to be raised to levels above the potential well and thus be emitted from the nucleus. The calculated number of emitted neutrons and protons is in qualitative agreement with the experimental results for the emission of scission neutrons and protons. However, there is a large energy transfer from the collective to the single-particle degrees of freedom and hence the transition cannot be considered adiabatic for this time scale. The inclusion in the model of a residual interaction is expected to reduce both the number of particles emitted and the energy transfer from the collective to single-particle degrees of freedom, thus making the transition more nearly adiabatic.

This publication has 9 references indexed in Scilit: