αdecay studies of the nuclides195Rnand196Rn

Abstract

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 $\ensuremath{\alpha}$ decaying isomeric states, with ${E}_{\ensuremath{\alpha}}=7536(11)\mathrm{keV}[{T}_{1/2}{=(6}_{\ensuremath{-}2}^{+3})\mathrm{ms}]$ for the ground state and ${E}_{\ensuremath{\alpha}}=7555(11)\mathrm{keV}[{T}_{1/2}{=(5}_{\ensuremath{-}2}^{+3})\mathrm{ms}]$ for an isomeric state were identified in ${}^{195}\mathrm{Rn}.$ In addition, the half-life and $\ensuremath{\alpha}$ 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 $N=110.$