Rates for some reactions involving 42Ca and 44Ca

Ground-state reaction rates have been deduced from recent cross section measurements for the 42CA(α, n)45Ti, 42Ca(p, γ)43Sc, and 44Ca(p, n)44Sc reactions. Comparison of these rates with those calculated from a statistical model of nuclear reactions. (Woosley et al) shows good agreement for the first two, but the 44Ca(p, n) rate is more than a factor of 2 less than the theoretical prediction. Stellar reaction rates have been derived from the ground-state rates by multiplying the ground-state rates by the ratio of stellar to ground-state rates given by the statistical model. Both ground-state and stellar rates have been represented by analytic functions of the temperature. The role of these reactions in the approach to quasi-equilibrium during explosive silicon burning is discussed