The heavy element yields of neutron capture nucleosynthesis

An effort has been made to determine the contributions of the S- and R-processes of nucleosynthesis to the abundances of the heavy element isotopes. It has been concluded that the general prvious assumption concerning the exclusive assignment of isobars to one or the other of these processes is probably in error. The R-process abundances are characterized by relatively small fluctuations in the abundances of odd and even mass numbers. If this is always true, and such is assumed here, then there are substantial S-process contributions to the abundances of 'R-process' isobars. This is consistent with transient flashing episodes in the S-process neutron production processes. The primary tool for the separation of the abundances due to the two processes therefore had to be achievement of a reasonably smooth and monotonically-decreasing curve of the abundance of the S-process yields times the neutron capture cross-sections versus mass number. Tables of the separate yields are given. (orig.)