Spin assignments in 33S from the reaction 32S(d,p) 33S

Abstract

The gamma rays emitted in the decay of several of the low-lying states of 33S have been observed in coincidence with the proton groups populating these states in the reaction 32S(d,p) 33S. Angular correlations obtained between the protons, detected at 0° with respect to the incident beam, and the gamma rays were analysed by the method of Litherland and Ferguson to determine the spins and population parameters of the 1.965, 2.313, 2.937 and 3.224 MeV states of 33S, as well as the multipole mixing ratios and branching ratios of the gamma-ray transitions. The following results were obtained using a deuteron bombardment energy E d = 2.541 MeV. The 3.224 MeV state has spin 3 2 and decays to the ground state and the first excited state. The 2.937 MeV state has spin 7 2 and decays with equal intensitiesto the ground state and the 1.965 MeV state. The 2.313 MeV state has a probable spin 3 2 and decays to the ground state and the first excited state. The 1.965 MeV state has spin 5 2 and decays only to the ground state. There is some evidence for the presence of a state at 1.35 MeV, which may be the 5 2 + state predicted at 1.38 MeV. It appears to decay by a two step transition with γ-ray energies of 0.51 and 0.84 MeV; this, together with the weakness of the proton group, causes the identification to remain tentative at present.