  All of the actinides and roughly half the natural abundance of elements with
mass number A > 70 come from the rapid neutron capture process, or the
r-process. If the r-process, as suggested by many, occurs deep in a supernova,
then it is under the influence of an intense neutrino flux. Here we discuss the
effects of both charged-current and neutral-current neutrino interactions on
the r-process. We show that the multiple-neutron emission induced by both kinds
of neutrino interactions can affect the observed r-process abundance pattern
significantly. In particular, we find that five nuclei below the r-process
abundance peak at A = 195 may be entirely attributed to the neutrino-induced
neutron spallation processes following the r-process freeze-out. Furthermore,
the deduced neutrino fluence agrees with the conditions in the recent supernova
r-process model. These results strongly argue that the r-process occurs in
supernovae. They also provide a sensitive probe for the conditions at the
supernova r-process site.
