Optical polarization of neutron-rich sodium isotopes and β-NMR measurements of quadrupole moments

The nuclear quadrupole moments of neutron-rich sodium isotopes are being investigated with the help of in-beam polarization by optical pumping in combination with β-NMR techniques. First measurements have yielded the quadrupole splittings of NMR signals in the lattice of LiNbO3 for the isotopes 26Na, 27Na and 28Na. Interaction constants and ratios of the electric quadrupole moments are derived. In view of future experiments, β-decay asymmetries for the sequence of isotopes up to the N=20 neutron shell closure, 26-31Na, have been measured. (orig.)