Si29(α, n)S32reaction from 2.15 to 5.25 MeV bombarding energy

Levels in the compound nucleus ${}_{}{}^{33}{}_{}{}^{}\mathrm{S}$ have been investigated by measuring the reaction cross section for the reaction ${}_{}{}^{29}{}_{}{}^{}\mathrm{Si}(\alpha , n){}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ for incident $\alpha$ energies from 2.15 to 5.25 MeV, mostly in steps of 2.5 keV, using a $4\pi$-geometry neutron counter. One hundred and thirty-four resonances have been identified. The reciprocity theorem has been used to calculate the total cross section for the inverse reaction ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}(n, \alpha ){}_{}{}^{29}{}_{}{}^{}\mathrm{Si}$. Total widths have been determined for 107 resonances, and partial widths ${\Gamma }_{\alpha }$, ${\Gamma }_n$ and corresponding reduced widths ${{\gamma }_{\alpha }}^2$, ${{\gamma }_n}^2$ have been extracted for 19 cases where spin values are known. Statistical strength function analysis of the cross section under the excitation curve gave the averaged $\alpha$ particle strength function value as $〈{\overline{S}}_{\alpha }〉=0.067\mathrm{}\pm 0.012$ for this reaction.