Investigation of gamma ray transitions and lifetimes in35Cl

Abstract

Fortyeight resonances of the 34S(p, y)aSCl reaction in the proton range Ep= 1 --2 MeV have been observed. Gamma decay of twentyeight of these was investigated by means of a 55 em 3 Ge(Li) detector, and the energies and branching ratios of several bound states have been determined. The Q-value was found to be 6367.0_ 1.5keV. The lifetimes 150__20, 400__+140, 19-t-4, 14-t-2, 145+50, 20+5, 20+4, 42+4 and 7-1-3 fs were determined with the DSA method for the states at 1219, 1763, 2694, 3003, 3944, 3967, 4059, 4178 and 4882 keV, respectively. The experimental transition strengths were found to be in agreement with those given by manyparticle shell-modell calculations.

First spin-parity constraint of the 306 keV resonance in Cl35 for nova nucleosynthesis

“…For a variation in rate of a factor of ±100, a reasonable assumption as the rate used is the result of a theoretical statistical model with no experimental input, the final abundances of several key nuclei, including 34 S, 35 Cl, and 37 Ar, were found to vary by as much as 10-100X. Some presolar grains are known to condense in the ashes of novae [2,3], making observed isotopic ratios into "thermometers" of the explosion; for masses above A∼ 20, these ratios are influenced by po-§ current address: FLIR Systems Inc., Oak Ridge, Previous studies of the 34 S(p,γ) reaction [4][5][6][7][8][9][10] have mostly focused on energies 1-3 MeV above the proton threshold at 6370.6 keV [11], higher in energy than is relevant to most astrophysical scenarios including novae. One direct measurement [10] was able to determine the strength of a resonance of unknown spin/parity in 34 S+p around E r = 500 keV, but direct measurements at lower energies will become increasingly difficult, with cross sections dropping by orders of magnitude as the Gamow window is approached.…”

Evidence for a breakdown of the isobaric multiplet mass equation: A study of theA=35,T=3/2isospin quartet

“…A detailed analysis of the excited state of 35 Cl and a discussion of the separation and the spin assignment of the two 5.65-MeV states can be found in [56]. The excitation energy resulting from the mean values of the data gives the respective energies of 5646 (2) keV and 5654 (2) keV.…”

“…For the excited state of 35 Cl, as summarized in [31], the experimental data are not precise enough and show as well some discrepancies (see [53] and references therein). The energy level scheme of 35 Cl exhibits a 'double' peak around 5.65 MeV, which has been thoroughly investigated [53,54,55,56,57]. Previous work on the IMME showed that the energy of the excited state for 33 Cl was wrongly calculated from the center-of-mass to the laboratory frame [8].…”