Photodisintegration of 80Se: Implications for the s-process branching at 79Se

Photoneutron cross sections were measured for Se-80 immediately above the neutron separation energy with quasimonochromatic gamma-ray beams to experimentally constrain the E1 gamma strength function for Se-80. Two sets of the gamma strength function and the level density that equally meet the experimental constraint predict largely different neutron capture cross sections for Se-79. Based on the Maxwellian-averaged cross sections of the latest compilation complemented with the predicted cross sections for Se-79, we calculated sigma N values of the main s-process component using a phenomenological model and deduced empirical abundances of the weak s-process component. An attempt is made of considering the implications of the abundance ratios of Kr-80 and Kr-82 within the framework of phenomenological models for the weak s process.