Multifragmentation in the 4.8-GeV${\mathrm{}}^3$He $+$ ${}^{\mathrm{nat}}$Ag, ${}^{197}$Au Reactions

Multifragmentation of ${}^{\mathrm{nat}}$Ag and ${}^{197}$Au nuclei induced by a 4.8-GeV${\mathrm{}}^3$He ions has been studied with the Indiana Silicon Sphere $4\pi$ detector array. Rapidity and moving source analyses are consistent with thermal emission from a source in approximate kinetic equilibrium. For the most dissipative collisions, the spectral Coulomb peaks are broadened to very low energies, indicative of emission from an extended nuclear system. Predictions of a model with an intranuclear cascade and an expanding, emitting source compare well with experimental multiplicity distributions and the evolution of fragment spectral shapes.