LIFETIMES OF S-32 LEVELS

Mean lifetimes of 20 out of 31 bound levels in S-32 below an excitatio n energy of 8.0 MeV are deduced from the Doppler-broadened gamma-ray L ine shapes produced in the reactions H-2(P-31,n gamma)S-32, Si-28(Li-6 ,pn gamma)S-32, and (31)p(p,gamma)S-32. Of the 20 levels, lifetimes fo r 4 are reported here for the first time. For the remaining 16 levels, the lifetime values obtained in this work are considered to be more r eliable and accurate than those reported in the literature. Compared t o lifetime measurements reported in the literature, significant proced ural improvements have been made by (i) using the entire line shape in the data analysis, (ii) making measurements with targets implanted in high-stopping-power media, and (iii) simulating with the Monte-Carlo method the slowing-down process, experimental conditions, and the dela yed feeding from higher levels to the level being analyzed. The low-ly ing portion of the level scheme, level lifetimes, gamma-ray branchings , E2/M1 mixing ratios, and reduced transition probabilities are compar ed with shell-model calculations. The reduced B(E2) values for 16 out of 18 transitions and B(M1) values for 5 out of 10 transitions are rep roduced to within a factor of 5. A one-to-one correspondence between 3 3 experimental and predicted states is established up to 8.2 MeV for b oth positive- and negative-parity states.