Beta-decay rates of highly ionized heavy atoms in stellar interiors

Beta-decay rates are computed for heavy nuclides (26≤Z≤83, 59≤A≤210) at stellar temperatures of 5 x 107≤T≤5 x 108 K and electron number densities of 1026≤n/sub e/≤3 x 1027 cm-3. The β-decay processes considered are: (i) electron emission (β- decay) into the continuum as well as into the bound state; (ii) positron emission (β+ decay); and (iii) capture of the orbital and free electrons. The degree of ionization is determined by solving the Saha equation corrected for the continuum depression within a finite-temperature Thomas-Fermi model. The adopted input atomic data are based on a self-consistent mean-field method. The ft values for unknown β transitions are estimated from systematics. The results will be most useful for s-process nucleosynthesis studies. copyright 1987 Academic Press, Inc