Neutron-$\gamma$ coincidence measurements, on the reaction ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}(\alpha ,n\gamma ){}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$, have been undertaken to identify transitions from some states in ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$ below 5 MeV excitation energy, and to measure their angular correlations and the lifetimes of the levels. The 4.466-MeV level was found to decay to the 2.572-MeV level, and the 4.522-MeV level to the 1.528-MeV level. These decays, together with the angular correlation and lifetime data, are consistent with assigning the 4.466-MeV level as the $4^{-}$ member of the negative-parity rotational band, based on the $1^{-}$ level at 2.211 MeV, and the 4.522-MeV level as the $7^{+}$ state of the ground-state rotational band. The data also support assigning the 3.708-MeV level as the $6^{+}$ member of the ground-state rotational band and the 4.708-MeV level as the $5^{+}$ member of the $T=0\mathrm{}$, $K=0\mathrm{}$ band, based on the $1^{+}$ state at 0.583 MeV. The electromagnetic properties of the ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$. levels are compared with the rotational model predictions and recent shell-model calculations.

• Received 15 May 1973

DOI:https://doi.org/10.1103/PhysRevC.8.2182