Limiting excitation energy in the reaction Si+Si

Abstract

We have measured energy and angular distributions of protons and α-particles in coincidence with evaporation residues for the reaction Si+Si at beam energies 12.4, 19.7, and 30.0 MeV/N. The reconstructed excitation energies of composite systems decaying into evaporation residues saturate near 3 MeV/N with increasing beam energy. This is consistent with a limiting excitation energy between 4 and 5 MeV/N above which sequential evaporation does not occur.