Structure of 65,67Co studied through the β decay of 65,67Fe and a deep- inelastic reaction

The neutron-rich isotopes Fe-65,Fe-67 and Co-65 have been produced at the LISOL facility, Louvain-La-Neuve, in the proton-induced fission of U-238. Beams of these isotopes have been extracted with high selectivity by means of resonant laser ionization combined with mass separation. Yrast and near-yrast levels of Co-65 have also been populated in the Ni-64+U-238 reaction at Argonne National Laboratory. The level structure of Co-65 could be investigated by combining all the information from both the Fe-65 and Co-65 decay and the deep-inelastic reaction. The Fe-65, Co-65, and Fe-67 decay schemes and the Co-65 yrast structure are fully established. The Co-65,Co-67 level structures can be interpreted as resulting from the coexistence of core-coupled states with levels based on a low-energy proton-intruder configuration.