Average angular momentum in fusion reactions deduced from evaporation-residue cross sections

Abstract

Average angular momenta of compound nuclei were deduced from measured evaporation-residue cross sections on the basis of statistical model calculations. We have applied this method to the following systems: {sup 4}He+{sup 197}Au, {sup 16}O+{sup 147,149,152,154}Sm, {sup 32}S+{sup 138}Ba, and {sup 48}Ti+{sup 122}Sn. For some of these systems, the average angular momenta were compared with those extracted from early {gamma}-multiplicity measurements. A reasonable agreement was found between the values of the deduced average angular momentum obtained from both methods, giving support to the validity of the present method. The average angular momenta for all the systems exhibit the energy dependence predicted by a standard fusion model calculation. {copyright} {ital 1998} {ital The American Physical Society}