β-decay studies of the transitional nucleus 75Cu and the structure of 75Zn

The beta decay of Cu-75 [t(1/2) = 1.222(8) s] to levels in Zn-75 was studied at the Holifield Radioactive Ion Beam Facility of Oak Ridge National Laboratory. The gamma gamma and beta gamma data were collected at the Low-energy Radioactive Ion Beam Spectroscopy Station using the high-resolution isobar separator to obtain a purified Cu-75 beam with a rate of over 2000 ions per second. The excited states in Zn-75 have been identified for the first time. A total of 120 gamma-ray transitions were placed in a level scheme containing 59 levels including two states above the neutron separation energy and a previously unknown 1/2(-) isomeric state at 127 keV. Spins and parities of several states were deduced and interpreted based on the observed beta feeding and gamma-decay pattern.