First in-beamγ-ray study of the level structure of neutron-richS39

Abstract

The neutron-rich 39 S nucleus has been studied using binary grazing reactions produced by the interaction of a 215-MeV beam of 36 S ions with a thin 208 Pb target. The magnetic spectrometer, PRISMA, and the γ -ray array, CLARA, were used in the measurements. Gamma-ray transitions of the following energies were observed: 339, 398, 466, 705, 1517, 1656, and 1724 keV. Five of the observed transitions have been tentatively assigned to the decay of excited states with spins up to (11/2 − ). The results of a state-of-the-art shell-model calculation of the level scheme of 39 S using the SDPF-U effective interaction are also presented. The systematic behavior of the excitation energy of the first 11/2 − states in the odd-A isotopes of sulfur and argon is discussed in relation to the excitation energy of the first excited 2 + states of the adjacent even-A isotopes. The states of 39 S that have the components in their wave functions corresponding to three neutrons in the 1f 7/2 orbital outside the N = 20 core have also been discussed within the context of the 0 ω shell-model calculations presented here.

Lifetime measurements of states of S35 , S36 , Grocutt1, Chapman2, Haas3 et al. 2022Phys. Rev. CSelf Cite3000View full textAdd to dashboardCite

“…Similarly, the measured lifetime of the 3 − state of 36 S at 4193 keV, 0.84(24) ps, is in very good agreement with the most recent published value of 0.9(1) ps [53]. In addition, the measured lifetime of the first 2 + state of 32 Si at an excitation energy of 4193 keV, namely 0.44 (11) ps [35], is in excellent agreement with the measurement of Guillaume et al [54], 0.48 (7) ps. Thus, five lifetime measurements based on data from the same experiment are in excellent agreement with previously published values, and this provides strong validation of the analysis methods used here.…”

“…In the earlier work, the combination of PRISMA [3,4], a large solid angle magnetic spectrometer to identify the projectile-like nuclear species, and CLARA [5], an array of escape-suppressed Ge γ -ray detectors to measure the γ -ray decay of the populated levels, was used. In relation to the isotopes of sulfur, the previous published works from the experiment have involved studies of the isotopes 37 S [6], 39 S [7], 40 S [8], and 41 S [9]. In addition, the level structures of other populated isotopes of sulfur were investigated [10].…”