Nuclear Structure of the Nickel Isotopes

The nickel isotopes are described in terms of strongly admixed spherical shell-model configurations of neutrons occupying the 2p3/2, 1f5/2, and 2p1/2 orbits. A set of effective-interaction matrix elements is deduced which accurately reproduces the spectra of the Ni isotopes from Ni⁵⁸ to Ni⁶⁷. The wave functions resulting from the calculation of the energy levels are then used to calculate the single-nucleon spectroscopic factors. These are in fairly good agreement with the experimental spectroscopic factors found in pickup and stripping experiments. In addition, some of the results from two-nucleon transfer reactions are compared with the predictions of the present model. Using the wave functions obtained and an effective charge for the neutron, the $E2$ transition probabilities in the even-mass isotopes of Ni are calculated and found to be in agreement with experimental facts.