Levels ofS36fromS34(t,p)S36

Levels of ${\mathrm{S}}^{36}$ have been investigated via the ${\mathrm{S}}^{34}\mathrm{}(t,p)\mathrm{}{\mathrm{S}}^{36}$ reaction, using targets of ${\mathrm{Sb}}_2$ ${\mathrm{S}}_3$ with the sulfur content enriched to 86% in the isotope ${\mathrm{S}}^{34}$. The excitation energies (given in MeV) of the levels observed, together with the restrictions on spins and parities resulting from this investigation and also previous work, are as follows: 3.29, $2^{+}$; 3.34, $0^{+}$; 4.19, $3^{-}$; 4.52, $1^{+}$; 4.57, $2^{+}$; 5.26, 1, 2, 3; 5.38, 1, 2, or (3); 5.50, 2, (3), 4; 5.57, 1, (2), 3; 6.20, 2, 3; 6.51, $4^{+}$; and 7.12, $1^{+}$ or $2^{+}$. Information on the $\gamma$-ray branching of these levels and on the angular-correlation patterns of major branches was obtained from two-parameter $p-\gamma$ coincidence studies utilizing collinear detection of the reaction protons. The 3.29-MeV level decays by $E2$ radiation directly to the ${\mathrm{S}}^{36}$ $J^{\pi }=0^{+}$ ground state. An intermediate-image pair spectrometer was used to determine that the 3.34-MeV level has $J^{\pi }=0^{+}$, since it decays by an $E0$ transition to the ground state. With the exception of the 4.52-, 5.38-, and 7.12-MeV levels, which decay mainly to the ground state, the higher-lying levels were observed to deexcite primarily by cascade transitions through the 3.29-MeV level. Ge(Li) studies of $\gamma$-ray Doppler shifts determine the following mean-lifetime restrictions for the indicated levels (excitations in MeV); 3.29, $\tau =0.20\mathrm{}\pm 0.03$ psec; 4.19, $\tau >2\mathrm{} \mathrm{psec}$; and 4.57, $\tau <0.1\mathrm{}$ psec. Additional but less restrictive limitations are given for several of the remaining levels. The lifetime of the $0^{+}$ 3.34-MeV state was measured by electronic techniques which determine a mean life $\tau =12.7\mathrm{}\pm 0.3$ nsec. The spin-parity limitations deduced herein are from a combination of the results of the angular-correlation analysis and these lifetime limitations. No evidence was obtained for the existence of states at 2.00 and 2.85 MeV previously reported from the ${\mathrm{S}}^{34}\mathrm{}(t,p)\mathrm{}{\mathrm{S}}^{36}$ reaction. Finally, the observed level structure as deduced from this and previous experiments is compared with relevant shell-model calculations on the even- and odd-parity states of this $T_z=2\mathrm{}$ nucleus.