Properties of Levels inCl34

Abstract

22 levels of Cl+ below E"=4. 7 MeV are populated by the y-ray decay of the three reso-.nances at E& --1058, 1098, and 1121 keV in the reaction S33(p, y)C1+. These resonances, selected for study because of their dominant modes of p decay to levels above 2.7 MeV for which hmited prior data exist, were investigated with an 80-cm 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, y-ray decay schemes and excitation energies with errors in the range from +0.3 to +2.3 keV were determined for 14 bound states in the range 2.3&E"&4. 7 MeV and the three resonance levels. The reaction Q value was determined with the result Q = 5139.9+ 0.9 keV. The following J~a ssignments (energies in MeV) result from the combination of the present work with a recent S33(Hes, d)C1+ study: 2.3. The resonance level assignments are J~(1058)=3, J~(1098)=4, and J~(1121)=1 . 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. =4 MeV, mere obtained. Unique spin assignments for two of the resonance levels and for the level at 2.2V6 MeV (8=4) were obtained by (p, yy) angularcorrelation measurements.From another recent S"(He',py}C1'4 investigation, DeLuca, Lawson, and Chagnon' report J'= 1 for the 2.581and 2.126-MeV levels and J =2 for the 2. 722-MeV level. In older work, Dong-Hyok' studied the reaction S"-

Shell-model relationships between negative-parity states of even-massA=30?40 nuclei

“…Our results III and IV are not subject to the doubt regarding the shell-model df structure of the T=I, 3 and 4-levels in 34S/C1, specifically that expressed by Erskine et al [13], who suggested that the 4.62MeV 3-level in 34S could be of collective nature, and by Hyder and Harris [14], who suggested that the 6.21MeV TJ'=14-level in 3~C1 (the analog of the 6.42MeV level in 3aS) is of non-pure character. Hyder and Harris [14] compared their experimental M1 strengths for A T=I transitions in 34C1 with theoretical values calculated from an analytical expression by Prosser and Harris [15] for df shell-model states.…”

Investigation of Nuclear Levels in34Cl

“…Some resonance states in T l decay mainly to high-lying states in contrast to the normal decay mode, where the states decay to lower-lying states. The ED = 1 058 and 1 018 keV resonances studied by Hyder and Harris [3] and the E, = 1 121 keV resonance studied by Glaudemans et al [l] are of this type. The decays of These states are of the type d,!,f,,,, T=o.…”

“…In contrast to this, the E, = 1 542 and 1 627 keV resonances decay to the highlying states. According to Hyder and Harris [3] the 4075 keV level populated strongly at Ep = 1 542 keV decays entirely to the 146 keV level. Three additional branches clearly seen in the Ep = 1 542 keV spectrum de-excite this state.…”

“…The gamma ray observed with lower energy feeds the state at E, = 2 377 keV ( J = 4+). The decay scheme of the Ep = l 098 keV resonance presented by Hyder and Harris [3] was revised at this point and is shown in Fig. 1.…”

“…Graber and Harris [2] examined resonances in the E, = 1 000-1 300 keV region with a 40 cm3 Ge(Li) detector. Recently they reported a study [3] where angular distribution and correlation measurements on the Ep = 1058, 1098 and 1 121 keV resonances have been performed. The bound-state properties in 34Cl have been studied in several particle-particle reaction measurements [4-91. Lifetime values for the states below 2.7 MeV have been reported by four groups [4, 5, 9, lo].…”