36Cl(n,p)36S cross section from 25 meV to 800 keV and the nucleosynthesis of the rare isotope 36S.

We have measured the [sup 36]Cl([ital n],[ital p])[sup 36]S cross section from thermal energy to approximately 800 keV. Parameters for eight resonances between 900 eV and 70 keV were determined in a multilevel fit to our data which also included information from published [sup 36]S([ital p],[gamma])[sup 37]Cl measurements. The [sup 36]Cl([ital n],[ital p])[sup 36]S reaction can play a critical role in the production of the rare isotope [sup 36]S in explosive nucleosynthesis and [ital s]-process calculations. The astrophysical rate for this reaction was calculated from our measured cross sections and was found to be significantly smaller than the theoretical rate used in previous nucleosynthesis calculations. We discuss the impact of this result on the nucleosynthesis of [sup 36]S.