Low-Lying Yrast States inRn210andRn211and the Competition between Neutron-Hole and Proton Excitations

The $\gamma$-decay and nuclear structure of low-lying yrast and near yrast levels in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Rn}$ and ${}_{}{}^{211}{}_{}{}^{}\mathrm{Rn}$ have been investigated. The cascade from the yrast $6^{+}$ state in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Rn}$ branches to two close-lying $4^{+}$ states, deduced to be complete mixtures of the $4^{+}$ states arising from the proton configuration, and from the neutron-hole intruder configuration. The influence of this proton-neutron-hole interaction on the yrast cascades in ${}_{}{}^{211}{}_{}{}^{}\mathrm{Rn}$ and ${}_{}{}^{206}{}_{}{}^{}\mathrm{Rn}$, ${}_{}{}^{208}{}_{}{}^{}\mathrm{Rn}$ is discussed.