Alpha decays of neutron deficient isotopes in the region N >~ 82 >~ Z.

Abstract

We compare \ensuremath{\alpha}-decay half-life calculations, using parameter values unchanged from previous work, with 88 recent measurements of neutron deficient isotopes in the region N\ensuremath{\gtrsim}82\ensuremath{\gtrsim}Z. The results generally reproduce the data to within a factor of 3 or better. Exceptions to this statement occur for decays which do not proceed by s-wave transitions, and also where no \ensuremath{\alpha}-branching ratio has been measured. In the former cases we calculate the L values for the transitions needed to bring their half-lives into agreement with the experimental values, and for the latter we predict branching ratio values based on the mismatches between the calculated \ensuremath{\alpha} half-lives and the measured total half-lives. Amongst the 88 reported decays there are no cases which cannot be accommodated satisfactorily within this framework. For completeness we also calculate proton emission half-lives and find excellent agreement with the two observations in $^{156}\mathrm{Ta}$ reported in the same experimental survey. \textcopyright{} 1996 The American Physical Society.