Primary-Fragment Angular Momenta in Deep-Inelastic Reactions

Abstract

$\ensuremath{\gamma}$- ray multiplicities $〈{M}_{\ensuremath{\gamma}}〉$ and energies $〈{E}_{\ensuremath{\gamma}}〉$ associated with identified products of completely damped collisions of 237-MeV $^{40}\mathrm{Ar}$ with $^{89}\mathrm{Y}$ are analyzed to determine the angular momenta of the primary heavy fragments. Extending the analysis to the system 175-MeV $^{20}\mathrm{Ne}$+Ag allows a comparison which indicates that different partial waves contribute in these two nearly identical composite systems at almost the same excitation energy and that the transition from fusion-evaporation to deep-inelastic reactions occurs over a wide range of partial waves.