Primary-Fragment Angular Momenta in Deep-Inelastic Reactions

Abstract

$\gamma$- ray multiplicities $〈M_{\gamma }〉$ and energies $〈E_{\gamma }〉$ 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.