The nuclear structure of ${}^{67}\mathrm{Co}$ has been investigated through ${}^{67}\mathrm{Fe}$ $\beta$ decay. The ${}^{67}\mathrm{Fe}$ isotopes were produced at the LISOL facility in proton-induced fission of ${}^{238}\mathrm{U}$ and selected using resonant laser ionization combined with mass separation. The application of a new correlation technique unambiguously revealed a $496(33)$ ms isomeric state in ${}^{67}\mathrm{Co}$ at an unexpected low energy of 492 keV. A ${}^{67}\mathrm{Co}$ level scheme was deduced. Proposed spin and parities suggest a spherical $(7/2^{-})$ ${}^{67}\mathrm{Co}$ ground state and a deformed first excited $(1/2^{-})$ state at 492 keV, interpreted as a proton 1p-2h prolate intruder state.

• Received 16 July 2008

DOI:https://doi.org/10.1103/PhysRevC.78.041307