Identification and decay of neutron-richS39

The previously unreported decay of ${}_{}{}^{39}{}_{}{}^{}\mathrm{S}$ has been studied from sources prepared in the ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}\mathrm{}(n,2p)\mathrm{}{}_{}{}^{39}{}_{}{}^{}\mathrm{S}$ reaction using intermediate energy neutrons. The ${}_{}{}^{39}{}_{}{}^{}\mathrm{S}$ half-life was measured to be 11.5 ± 0.5 sec. On the basis of results from $\gamma$ singles and coincidence measurements, all six $\gamma$ rays observed in ${}_{}{}^{39}{}_{}{}^{}\mathrm{S}$ decay were placed in a level scheme for ${}_{}{}^{39}{}_{}{}^{}\mathrm{Cl}$ consisting of excited states at 397, 1301, 1697, 1785, and 2571 keV. Our levels are compared with results from reaction studies and shell-model calculations and a discussion of the possible nature of the negative-parity states is given.