Breakup Densities of Hot Nuclei

Abstract

Breakup densities of hot $^{197}\mathrm{A}\mathrm{u}$-like residues have been deduced from the systematic trends of Coulomb parameters required to fit intermediate-mass-fragment kinetic-energy spectra. The results indicate emission from nuclei near normal nuclear density below an excitation energy ${E}^{*}/A\ensuremath{\lesssim}2\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}$, followed by a gradual decrease to a near-constant value of $\ensuremath{\rho}/{\ensuremath{\rho}}_{0}\ensuremath{\sim}0.3$ for ${E}^{*}/A\ensuremath{\gtrsim}5\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}$. Temperatures derived from these data with a density-dependent Fermi-gas model yield a nuclear caloric curve that is generally consistent with those derived from isotope ratios.