γ probe of nuclear dissipation

Abstract

The Langevin model is applied to investigate the roles of excitation energy and system size in the evolution of post-saddle giant dipole resonance (GDR) γ-ray multiplicity (Mγ) with post-saddle friction strength (β). It is demonstrated that Mγ is more sensitive to β at high energy. Furthermore, it is shown that the dependence of γ emission on friction is sensitive to the size of fissioning nuclei, and a large system size significantly increases the sensitivity. Our findings indicate that in experiments, to tightly constrain post-saddle dissipation through the γ probe, it is optimal to produce heavy fissioning systems with high energy.