Single-neutron orbits near Ni-78: Spectroscopy of the N=49 isotope Zn-79
Single-neutron states in the Z = 30, N = 49 isotope Zn-79 have been populated using the Zn-78(d,p)Zn-79 transfer reaction at REX-ISOLDE, CERN. The experimental setup allowed the combined detection of protons ejected in the reaction, and of y rays emitted by Zn-79. The analysis reveals that the lowest excited states populated in the reaction lie at approximately 1 MeV of excitation, and involve neutron orbits above the N = 50 shell gap. From the analysis of gamma-ray data and of proton angular distributions, characteristic of the amount of angular momentum transferred, a 5/2+ configuration was assigned to a state at 983 keV. Comparison with large-scale-shell-model calculations supports a robust neutron N = 50 shell-closure for Ni-78. These data constitute an important step towards the understanding of the magicity of 78Ni and of the structure of nuclei in the region. (C) 2014 The Authors. Published by Elsevier B.V.