Ingoing-wave Boundary-condition Versus Optical-model Transmission Coefficients - A Systematic Comparison With Particle-emission Data

Evaporative [sup 1,2,3]H and [sup 4]He yields and energy spectra have been analyzed in the framework of the statistical model in ten heavy-ion reactions, spanning composite systems with 20[lt][ital Z][lt]56. Transmission coefficients derived from the ingoing-wave boundary condition (IWBCM) or optical models (OM) have been used in the calculations. The effect of using different values of deformation parameters, level-density parameter [ital a] and radii of the real part of the transmission coefficient potentials has been investigated. Except for the low-energy side of the proton spectra, the shape of energy spectra are reasonably well reproduced by both sets of transmission coefficients. While the two models are essentially equivalent for [sup 1]H and [sup 4]He cross sections, they differ significantly in the prediction of [sup 2]H and [sup 3]H cross sections. OM transmission coefficients fail in reproducing [sup 2,3]H cross sections, unless no standard parameters are used, while IWBCM transmission coefficients provide a good overall agreement. The failure of the OM is ascribed to the inclusion of nonfusion reactions in the inverse process.