Low-spin states and the non-observation of a proposed 2202-keV, 0+ isomer in 68Ni

The low-spin level scheme of Ni-68 was investigated with the Gammasphere array following reactions between a Zn-70 beam and U-238, Pb-208, and Au-197 targets. Spin assignments for some states have been verified through gamma-ray angular correlations, including the 0(+) assignment for the 2511-keV level. Two previously unknown states at 3302 and 3405 keV have been identified. No evidence was found for a recently reported 216-ns, 0(+) isomer at 2202 keV that was attributed to a proton two-particle, two-hole intruder configuration, despite experimental conditions similar to those used in the measurement reporting its discovery.