Nuclear spins, magnetic moments, and quadrupole moments of Cu isotopes from N = 28 to N = 46: Probes for core polarization effects

摘要

Measurements of the ground-state nuclear spins and magnetic and quadrupole moments of the copper isotopesfrom 61Cu up to 75Cu are reported. The experiments were performed at the CERN online isotope mass separator(ISOLDE) facility, using the technique of collinear laser spectroscopy. The trend in the magnetic momentsbetween the N = 28 and N = 50 shell closures is reasonably reproduced by large-scale shell-model calculationsstarting from a 56Ni core. The quadrupole moments reveal a strong polarization of the underlying Ni core whenthe neutron shell is opened, which is, however, strongly reduced at N = 40 due to the parity change betweenthe pf and g orbits. No enhanced core polarization is seen beyond N = 40. Deviations between measured andcalculated moments are attributed to the softness of the 56Ni core and weakening of the Z = 28 and N = 28 shellgaps.