The levels of ${}_{}{}^{183}{}_{}{}^{}\mathrm{Re}$ and ${}_{}{}^{181}{}_{}{}^{}\mathrm{Re}$ have been studied through the ($\alpha ,2n\gamma$) and ($\alpha ,4n\gamma$) reactions with a ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$ target. Besides confirming and extending the levels of the ${\frac{5}{2}}^{+}\left[402\mathrm{}\uparrow \right]$ and ${\frac{9}{2}}^{-}\left[514\mathrm{}\uparrow \right]$ bands, two new members, ${\frac{21}{2}}^{-}$ and ${\frac{25}{2}}^{-}$, of the ${\frac{1}{2}}^{-}\left[541\mathrm{}\downarrow \right]$ band in ${}_{}{}^{183}{}_{}{}^{}\mathrm{Re}$ and existence and relative location of seven new members, ${\frac{5}{2}}^{-}$, ${\frac{9}{2}}^{-}$, ${\frac{13}{2}}^{-}$, ${\frac{17}{2}}^{-}$, ${\frac{21}{2}}^{-}$, ${\frac{25}{2}}^{-}$, and ${\frac{29}{2}}^{-}$, of the ${\frac{1}{2}}^{-}\left[541\mathrm{}\downarrow \right]$ band in ${}_{}{}^{181}{}_{}{}^{}\mathrm{Re}$ are established. A few new lifetimes are measured and some side feeding to the levels of the above bands is established.

NUCLEAR REACTIONS ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}(\alpha ,2n\gamma ){}_{}{}^{183}{}_{}{}^{}\mathrm{Re}$ and ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}(\alpha ,4n\gamma ){}_{}{}^{181}{}_{}{}^{}\mathrm{Re}$, $E_{\alpha }=25\mathrm{}-63$ MeV; measured $\sigma (\gamma ,E_{\alpha })$, $\sigma \left(\theta \right)$, $\gamma -\gamma$ coincidence, $\gamma -t$ distributions; deduced decay schemes, $J$, $\pi$, $T_{\frac{1}{2}}$.

• Received 25 February 1974

DOI:https://doi.org/10.1103/PhysRevC.10.656