Thermonuclear Reaction Rates for Proton Induced Reactions on exp 41 K and Neutron Induced Reactions on exp 41 Ca

摘要

The yield of gamma -rays from the reaction exp 41 K(p, gamma ) exp 42 Ca has been measured as a function of bombarding energy over the range 0.68-2.48 MeV and from the reaction exp 41 K(p, alpha gamma ) exp 38 Ar over the range 1.20-2.48 MeV, and the yield of neutrons from the reaction exp 41 K(p,n) exp 41 Ca has been measured from threshold to a bombarding energy of 2.48 MeV. The energy dependence of the cross sections is compared with statistical-model calculations with global optical model parameters in all particle channels. The calculations seriously overestimate the cross section for the neutron channel and underestimate those for the other channels. A reduction in the imaginary well depth in the neutron channel leads to good agreement with all the data. Statistical-model calculations with this modified set of parameters are then carried out to provide cross sections for the astrophysically interesting reactions exp 41 Ca(n,p) exp 41 K, exp 41 Ca(n, alpha ) exp 38 Ar, and exp 41 Ca(n, gamma ) exp 42 Ca. Thermonuclear reaction rates are calculated for all six reactions over the temperature range 5 x 10 exp 8 - 10 exp 1 0K which includes the range of temperatures of interest in nucleosynthesis calculations. (Atomindex citation 13:663665)