Lifetimes of Some Low-Lying Levels ofCr52

The mean lifetimes of levels of ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$ to 4.5 MeV in excitation energy have been measured by the Doppler-shift-attenuation method. States in ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$ were populated by the reaction ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}-({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$ at 11.0 MeV using natural vanadium targets. $\gamma$ rays were detected with a 37.5-${\mathrm{cm}}^3$ Ge(Li) detector at 30, 90, and 150° to the beam axis. The following mean lifetimes (in units of ${10}^{-13\mathrm{}}$ sec) were found: $\tau (1434\mathrm{}-\mathrm{k}\mathrm{e}\mathrm{V}\mathrm{l}\mathrm{e}\mathrm{v}\mathrm{e}\mathrm{l})={9.9}_{-2.5\mathrm{}}^{+4.5\mathrm{}}$, $\tau \mathrm{}\left(2369\right)={15.0}_{-2.5\mathrm{}}^{+5.0\mathrm{}}$, $\tau \mathrm{}\left(2766\right)={20}_{-5\mathrm{}}^{+7\mathrm{}}$, $\tau \mathrm{}\left(2965\right)={6.8}_{-1.9\mathrm{}}^{+3.2\mathrm{}},$ $\tau \mathrm{}\left(3114\right)>29\mathrm{}$, $\tau \mathrm{}\left(3162\right)={1.2}_{-0.4\mathrm{}}^{+0.6\mathrm{}}$, $\tau \mathrm{}\left(3414\right)={3.2}_{-0.7\mathrm{}}^{+1.2\mathrm{}}$, $\tau \mathrm{}\left(3469\right)>50\mathrm{}$, $\tau \mathrm{}\left(3472\right)>27\mathrm{}$, $\tau \mathrm{}\left(3617\right)>11\mathrm{}$, $\tau \mathrm{}\left(3947\right)={1.5}_{-0.4\mathrm{}}^{+0.6\mathrm{}}$, $\tau \mathrm{}\left(4015\right)={8.4}_{-2.5\mathrm{}}^{+4.6\mathrm{}}$, $\tau \mathrm{}\left(4040\right)={7.4}_{-2.0\mathrm{}}^{+3.6\mathrm{}}$, $\tau \mathrm{}\left(4563\right)={3.9}_{-0.9\mathrm{}}^{+1.7\mathrm{}}$. The lifetime results combined with the results of previous particle-$\gamma$ correlation experiments indicate $J^{\pi }=4^{+} \mathrm{and} 5^{+}$ for the 3414- and 4015-keV levels, respectively.