New Evaluation of Fission-Fragment Angular Distributions in Heavy-Ion Reactions

Measured fragment angular distributions for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$- and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$-induced fission are compared to calculations assuming $K$ to be determined at the saddle point and using moments of inertia from calculated saddle-point shapes with diffuse surfaces. These calculations are consistent with experimental angular distributions in those cases where the fission barrier is comparable to or greater than the temperature at the saddle point. When the temperature exceeds the barrier height, the overall agreemtn with experiment is poor.