The level structure of ${}^{211}\mathrm{Pb}$ has been studied using the $\alpha$ decay of ${}^{215}\mathrm{Po}$ in secular equilibrium with ${}^{219}\mathrm{Rn}$. Extremely weak $\alpha$’s and coincident $\gamma$ rays populate six new levels and a considerable fraction of the ${(g}_{9/2}{)}^3$ configuration in ${}^{211}\mathrm{Pb}$. Previous calculations of the ${(g}_{9/2}{)}^3$ configuration in ${}^{211}\mathrm{Pb}$ fit nicely with the observed states and suggest spins and parities. Comparison of the low-lying experimental states in ${}^{211}\mathrm{At}$ and ${}^{211}\mathrm{Pb}$ show considerable similarity which is presumably due to the ${\mathrm{}(9/2)\mathrm{}}^3$ configuration.

• Received 13 May 1998

DOI:https://doi.org/10.1103/PhysRevC.58.3223