The new neutron deficient nuclide ${}^{195}\mathrm{Rn}$ and the nuclide ${}^{196}\mathrm{Rn}$ have been produced in fusion evaporation reactions using ${}^{56}\mathrm{Fe}$ ions on ${}^{142}\mathrm{Nd}$ targets. A gas-filled recoil separator was used to separate the fusion products from the scattered beam. The activities were implanted in a position sensitive silicon detector. The isotopes were identified using spatial and time correlations between implants and decays. Two $\alpha$ decaying isomeric states, with $E_{\alpha }=7536\mathrm{}\left(11\right)\mathrm{}\mathrm{keV}\left[T_{1/2}{=(6\mathrm{}}_{-2}^{+3\mathrm{}}\right)\mathrm{ms}]$ for the ground state and $E_{\alpha }=7555\mathrm{}\left(11\right)\mathrm{}\mathrm{keV}\left[T_{1/2}{=(5\mathrm{}}_{-2}^{+3\mathrm{}}\right)\mathrm{ms}]$ for an isomeric state were identified in ${}^{195}\mathrm{Rn}.$ In addition, the half-life and $\alpha$ decay energy of ${}^{196}\mathrm{Rn}$ were measured with improved precision. The reduced widths deduced for the neutron deficient even-mass Rn isotopes suggest an onset of substantial deformation at $N=110.\mathrm{}$

• Received 22 December 2000

DOI:https://doi.org/10.1103/PhysRevC.63.044315