Laser spectroscopy investigation of the nuclear moments and radii of lutetium isotopes

Collinear laser spectroscopy experiments in the LuI transition 5d6s(2) D-3/ 2 --> 5d6s6p D-2(3/2) were performed on all lutetium isotopes in the range of Lu161-179. The nuclear spins, magnetic moments and quadrupole moments we re determined from the hyperfine structures observed for 19 ground states a nd 11 isomers. Variations in the mean square charge radii as a function of neutron number were obtained from the isotope shifts. These data considerab ly extend the systematics of the properties of nuclei in the upper rare-ear th region. A particular feature is the appearance of high-spin and low-spin ground states and isomeric states in the vicinity of the stable Lu-175, pa rtly arising from aligned neutron pairs. The results clearly show that the deformation properties are nearly independent of the occupancy and the coup ling of single-particle states. Theoretical predictions of deformation are confirmed in a consistent description of the measured radii and quadrupole moments. For all observed states, the spins and magnetic moments allow the assignment of rather pure Nilsson configurations.