Configurations and level structure of215Po

The level structure of ${}^{215}\mathrm{Po}$ has been studied by observing the alpha decay of ${}^{219}\mathrm{Rn}$ and coincident gamma rays and electrons. In addition to some new levels, some additional tentative spin and parities are observed. Quite different alpha decay hindrance factors make possible the assignment of $\pi {(h}_{9/2}{)}^2\nu {(g}_{9/2}{)}^5$ plus residual reflection asymmetric configurations to one set of states and $\pi {(h}_{9/2}{)}^2\nu {(g}_{9/2}{)}^4{i}_{11/2}$ plus residual configurations to another set of states. These configuration assignments are further studied by a comparison of the systematics of the ${}^{215}\mathrm{Po}$ levels with those of neighboring odd neutron nuclei. In this way the nature of the collapse of the reflection asymmetric configurations into the less degenerate shell model configurations can be studied.