Light charged particle and intermediate mass fragment emission in the reaction 640 MeV 86Kr+63Cu.

Abstract

Light charged particles from the reaction 640 MeV {sup 86}Kr+{sup 63}Cu have been measured in singles and in coincidence with intermediate mass fragments, fissionlike fragments, and other light charged particles. Multiplicities for {sup 1}H and {sup 4}He in association with the evaporation residues, fragments, and intermediate mass fragments have been determined. Composite nuclei, most of which decay to evaporation residues, are the major sources of evaporative light-charged particle emission. Average multiplicities for prescission {sup 1}H and {sup 4}He can be associated with the composite nucleus {ital en} {ital route} to scission; they are relatively large and thus suggest a time scale for fission longer than that for evaporation. The multiplicities for {sup 1}H and {sup 4}He in association with the intermediate mass fragments indicate that these fragments are usually born with a significant quantity of excitation energy. These multiplicities are used to estimate the primary masses and kinetic energies of the intermediate mass fragments.