Neutrino Spallation Reactions on 4He and the r-Process

We study the effects of neutrino spallation of neutrons and protons from ⁴He during the r-process. These reactions tend to hinder the r-process by allowing the assembly of too many heavy see nuclei. In order to make sufficient quantities of high-mass nuclei, the current r-process models seem to require temperatures for the mu and tau neutrinos of less than or roughly 6 MeV, although this is a very preliminary conclusion. More study of this interesting effect is definitely required. Nonetheless, we can at present conclude that these reactions should be included in calculations of the r-process in neutrino-driven winds and that we may be able to obtain from nucleosynthesis interesting constraints on the neutrino cooling of neutron stars.