Neutron production and neutron-capture nucleosynthesis in a low-mass, low-metallicity asymptotic giant branch star

Results are presented of stellar evolution calculations for a low-mass low-metallicity thermally pulsing AGB model star. It is shown that the controlling factor in determining neutron densities in the region of neutron-capture nucleosynthesis is the rate at which C-13 is introduced into the convective shell during the early stages of a thermal pulse. It is also shown that, after several pulses, the neutron-irradiated material is characterized by an exposure parameter that is very similar to that characterizing the heavy elements observed in solar system material and in some AGB stars.