Stellar cross sections for ${}_{}{}^{33}{}_{}{}^{}\mathrm{S}$(n,α${)}^{30}$Si, ${}_{}{}^{36}{}_{}{}^{}\mathrm{Cl}$(n,p${)}^{36}$S, and ${}_{}{}^{36}{}_{}{}^{}\mathrm{Cl}$(n,α${)}^{33}$P and the origin of ${}_{}{}^{36}{}_{}{}^{}\mathrm{S}$

The cross section of the ${}_{}{}^{33}{}_{}{}^{}\mathrm{S}$(n,α${)}^{30}$Si reaction was measured in a neutron energy spectrum yielding the stellar rate for a thermal energy of kT=25 keV. For the ${}_{}{}^{36}{}_{}{}^{}\mathrm{Cl}$(n,p${)}^{36}$S reaction, the experiment was performed in the neutron energy range from 10 to 260 keV. Our new result for ${}_{}{}^{33}{}_{}{}^{}\mathrm{S}$ resolves the problem of a large discrepancy between two previous experiments. In case of ${}_{}{}^{36}{}_{}{}^{}\mathrm{Cl}$ it could be shown that the (n,α) channel is negligibly small compared to the (n,p) reaction at s-process conditions. The present results are used for a detailed discussion of a possble s-process origin of the rare neutron-rich isotope ${}_{}{}^{36}{}_{}{}^{}\mathrm{S}$.