NEUTRINO-INDUCED NUCLEOSYNTHESIS AND THE SITE OF THE R-PROCESS

If the r process occurs deep within a type II supernova, probably the most popular of the proposed sites, abundances of r-process elements m ay be altered by the intense neutrino flux. We point out that the effe cts would be especially pronounced for eight isotopes that can be effi ciently synthesized by the neutrino reactions following r-process free ze-out. We show that the observed abundances of these isotopes are ent irely consistent with neutrino-induced nucleosynthesis, strongly argui ng for a supernova r-process site. The deduced neutrino fluences place stringent constraints on the freeze-out radius and dynamic time scale of the r process.