Abundances of the Rare-Earth Nuclei Produced by Rapid Neutron Capture in Supernovae

Abstract

Calculations have been carried out, following the method of Burbidge, Burbidge, Fowler, and Hoyle, for the abundances of nuclei in the rare-earth region which are produced in the rapid neutron-capture process thought to occur in supernovae. The recently available rare-earth mass differences of Johnson and Bhanot were employed. The calculated abundances agree, in general, with those given by Suess and Urey. The results of the computations support the work of Burbidge, Burbidge, Fowler, and Hoyle which showed the effect of spheroidal deformation above the closed shell at $N=126\mathrm{}$ in enhancing the production of ${\mathrm{Th}}^{232}$, ${\mathrm{U}}^{235}$, ${\mathrm{U}}^{238}$, ${\mathrm{Cf}}^{254}$, etc., in supernovae. The effect of different combinations of temperature and neutron density in enhancing certain relative abundances is discussed briefly.