Properties of Levels inCl34

Abstract

22 levels of ${\mathrm{Cl}}^{34}$ below ${E}_{x}=4.7$ MeV are populated by the $\ensuremath{\gamma}$-ray decay of the three resonances at ${E}_{p}=1058, 1098, \mathrm{and} 1121$ keV in the reaction ${\mathrm{S}}^{33}(p,\ensuremath{\gamma}){\mathrm{Cl}}^{34}$. These resonances, selected for study because of their dominant modes of $\ensuremath{\gamma}$ decay to levels above 2.7 MeV for which limited prior data exist, were investigated with an 80-${\mathrm{cm}}^{3}$ Ge(Li) detector, and with Ge(Li)-NaI coincidence and angular-correlation techniques. The results obtained for levels below 2.3 MeV are in general agreement with other recent work. A new result is a probable $J=3$ assignment for the 2.180-MeV level. For higher-lying levels, $\ensuremath{\gamma}$-ray decay schemes and excitation energies with errors in the range from \ifmmode\pm\else\textpm\fi{}0.3 to \ifmmode\pm\else\textpm\fi{}2.3 keV were determined for 14 bound states in the range $2.3<{E}_{x}<4.7$ MeV and the three resonance levels. The reaction $Q$ value was determined with the result $Q=5139.9\ifmmode\pm\else\textpm\fi{}0.9$ keV. The following ${J}^{\ensuremath{\pi}}$ assignments (energies in MeV) result from the combination of the present work with a recent ${\mathrm{S}}^{33}({\mathrm{He}}^{3},d){\mathrm{Cl}}^{34}$ study: 2.72, ${2}^{\ensuremath{-}}$; 3.55, ${3}^{\ensuremath{-}}$; 3.60, ${4}^{(\ensuremath{-})}$; 3.63, ${5}^{\ensuremath{-}}$; 3.77, ${1}^{\ensuremath{-}}$; 3.98, ${3}^{\ensuremath{-}}$; 4.08, ${4}^{\ensuremath{-}}$; 4.14, 2; 4.35, probably ${1}^{\ensuremath{-}}$; 4.42, 1, 2, or 3; 4.51, probably ${2}^{\ensuremath{-}}$; and 4.64, 2, 1, or 3. The resonance level assignments are ${J}^{\ensuremath{\pi}}(1058)={3}^{(\ensuremath{-})}$, ${J}^{\ensuremath{\pi}}(1098)={4}^{(\ensuremath{-})}$, and ${J}^{\ensuremath{\pi}}(1121)={1}^{\ensuremath{-}}$. It is shown that the three resonances are probably each odd-parity $T=1$ levels. The probable shell-model configurations of some of the odd-parity levels are discussed.