The r-process in the hot bubble

The high-entropy, evacuated region forming just outside the proto-neutron star during a core-collapse supernova makes an excellent site for the r-process. The high entropy per baryon allows this region to have a high free neutron/seed nucleus ratio, a necessary requirement for the r-process, even though the material is not particularly neutron rich. The neutrino-driven wind blowing from the hot bubble lasts several seconds and has a mass loss rate of roughly 10^-5 M_(.) s^-1. The total mass of r-process matter produced during the supernova is thus approximately 10^-4 M_(.), in good agreement with arguments from galactic chemical evolution. The hot-bubble r-process achieves local steady beta flow, in agreement with results from experimental nuclear physics. Deficiencies in the present model may reflect in part failings of the nuclear mass extrapolation used. It may be possible to constrain nuclear and neutrino physics through the r-process.