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Measurements of the ground-state nuclear spins, magnetic and quadrupole moments of the copper isotopes from 61Cu up to 75Cu are reported. The experiments were performed at the ISOLDE facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the N=28 and N=50 shell closures is reasonably reproduced by large-scale shell-model calculations starting from a 56Ni core. The quadrupole moments reveal a strong polarization of the underlying Ni core when the neutron shell is opened, which is however strongly reduced at N=40 due to the parity change between the $pf$ and $g$ orbits. No enhanced core polarization is seen beyond N=40. Deviations between measured and calculated moments are attributed to the softness of the 56Ni core and weakening of the Z=28 and N=28 shell gaps., 13 pagers, 19 figures, accepted by Physical Review C

Collinear laser spectroscopy was performed on Ga (Z = 31) isotopes at ISOLDE, CERN. A gas-filled linear Paul trap (ISCOOL) was used to extend measurements towards very neutron-rich isotopes (N = 36-50). A ground state (g.s.) spin I = 1/2 is measured for Ga-73, being near degenerate with a 3/2(-) isomer (75 eV less than or similar to E-ex less than or similar to 1 keV). The Ga-79 g.s., with I = 3/2, is dominated by protons in the pi f(5/2) orbital and in Ga-81 the 5/2(-) level becomes the g.s. The data are compared to shell-model calculations in the f(5/2)pg(9/2) model space, calling for further theoretical developments and new experiments. ispartof: Physical Review Letters vol:104 issue:25 pages:1-5 ispartof: location:United States status: published