Lifetimes and decays of energy levels in 60Ni

The Doppler shift attenuation technique was used to investigate the lifetimes of 33 states of ⁶⁰Ni up to 5.6 MeV of excitation; 18 were measured for the first time. Gamma rays from the ⁶⁰Ni(p,p′ψ) reaction were observed in coincidence with protons by two Ge(Li) detectors at 40° and 130° lab. We find a new doublet (3.381–3.393 MeV) and give several previously unknown ψ-ray branching ratios; the lifetimes allow one to attribute some spins or parities or to reject other assignments. In order to complement the existing information on ⁶⁰Ni, we have studied the proton configuration by the ⁵⁹Co(³He,dψ) reaction. The results are different from those expected from simple 1p-1h states of the proton core; many of the levels observed are multiplets decaying by cascades.