SURVEY OF R-PROCESS MODELS

We present a large survey of r-process nucleosynthesis models. The par ameters varied are the initial electron-to-baryon ratio, Y-e, the entr opy per baryon, s, and the dynamical timescale, tau(0). These quantiti es usefully characterize the abundances expected from any explosive ev ent. The calculations were strictly adiabatic in the sense that s was held constant throughout, which is more realistic than the standard rh o proportional to T3 parameterization. We also assumed steady mass los s and a radial outflow at constant velocity. By focusing on production of the r-process isotopes with mass near A = 195, one of the peaks in the solar system's r-process distribution, we provide constraints on the conditions necessary for production of these isotopes. These const raints should prove useful to supernova modelers seeking the r-process site.