Study of the Low-Lying States ofCl39via the ReactionCl37(t,pγ)Cl39

A Ge(Li) detector was used to measure $\gamma$-ray transitions in ${}_{}{}^{39}{}_{}{}^{}\mathrm{Cl}$ via proton-$\gamma$ coincidence studies in the ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}(t,p\gamma ){}_{}{}^{39}{}_{}{}^{}\mathrm{Cl}$ reaction at $E_t=3.4\mathrm{}$ MeV. Measurements were carried out with the proton detector centered at 180° and the $\gamma$-ray detector at 90° and 0° to the beam. Excitation energies and $\gamma$-ray branching ratios were determined for the first 14 levels of ${}_{}{}^{39}{}_{}{}^{}\mathrm{Cl}$. The mean lives of these ${}_{}{}^{39}{}_{}{}^{}\mathrm{Cl}$ states were deduced from the Doppler-shift attenuations observed in the primary transitions. The excitation energies (in keV) and mean lives (in psec) resulting from these measurements are as follows: 396 (> 2.0), 1301 (> 3.0), 1695 (${1.1}_{-0.5\mathrm{}}^{+1.4\mathrm{}}$), 1722 (0.44 ± 0.09), 1745 (1.3 ± 0.4), 1786 (>2.0), 2061 (1.8), 2490 (0.10 ± 0.05), 2586 (1.8), 3116 (0.21 ± 0.06), and 3534 (<0.2).