Gamma-ray spectroscopy studies of the lower excited states ofV53

Previously unobserved $\gamma$-ray decay modes of some excited states of ${}_{}{}^{53}{}_{}{}^{}\mathrm{V}$ were studied using the ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}(t,p\gamma ){}_{}{}^{53}{}_{}{}^{}\mathrm{V}$ reaction at a bombarding energy of $E_t=2.9\mathrm{}$ MeV. Reaction proton-$\gamma$-ray time coincident spectra were obtained using a variety of $\gamma$-ray detectors: a 10-cm × 10-cm NaI(Tl) detector, a 4-mm × 3.81-cm NaI(Tl) detector, a 3.81-cm × 5.08-cm NE102 plastic scintillator, and a 20-${\mathrm{cm}}^3$ Ge(Li) detector. Lifetime information was deduced from both Doppler-shift attenuations obtained from the Ge(Li) $\gamma$-ray spectra, and direct measurements using the plastic scintillator for the $\gamma$-ray detector. Some of the measured excitation energies $E_x$ (keV) and lifetimes ${\tau }_m$ are: (127.0 ± 1.4, ≤ 1 nsec); (227.8 ± 1.6, 5.85 ± 0.44 nsec); (1090.3 ± 2.0, $2 \mathrm{psec}\le {\tau }_m\le 1 \mathrm{nsec}$); (1265.4 ± 1.2, $1.6 \mathrm{psec}\le {\tau }_m\le 1 \mathrm{nsec}$); (1549.6 ± 3.0, ${0.11}_{-0.07\mathrm{}}^{+0.12\mathrm{}}$ psec); (1652.5 ± 3.4, ≥ 0.65 psec); and (1856.2 ± 2.4, ≤ 0.04 psec). The experimental results were interpreted with respect to existing nuclear-model calculations and tentative spin assignments were made for a number of excited states.