THEORY OF NUCLEAR MULTIFRAGMENTATION .2. POSTTRANSITION DYNAMICS

Recently, expressions were derived for the rate at which a highly excited nucleus breaks up into several interacting prefragments. The present work treats the dynamical evolution of the system subsequent to such a transition. The post-transition system is described as a number of distinct prefragments that experience both conservative and dissipative pairwise interactions, obtained by a suitable generalization of the dynamics governing damped nuclear reactions. The post-transition dynamics has a significant effect on the disassembly process. Most importantly, some prefragments may fuse in the course of the evolution, thus reducing the heavy-fragment multiplicity. The nuclear dissipation enhances this effect, while the survival probability of a specific mass partition is significantly increased when the source is endowed with an overall radial flow. © 1990 Elsevier Science Publishers B.V.