The magnetic moment of 11 Be (T 1͞2 13.8 s) was measured by detecting nuclear magnetic resonance signals in a beryllium crystal lattice. The experimental technique applied to a 11 Be 1 ion beam from a laser ion source includes in-beam optical polarization, implantation into a metallic single crystal, and observation of rf resonances in the asymmetric angular distribution of the b decay (b-NMR). The nuclear magnetic moment m͑ 11 Be͒ 21.6816͑8͒ m N provides a stringent test for theoretical models describing the structure of the 1͞2 1 neutron halo state.

High-precision mass and charge radius measurements on ;{17-22}Ne, including the proton-halo candidate 17Ne, have been performed with Penning trap mass spectrometry and collinear laser spectroscopy. The 17Ne mass uncertainty is improved by factor 50, and the charge radii of ;{17-19}Ne are determined for the first time. The fermionic molecular dynamics model explains the pronounced changes in the ground-state structure. It attributes the large charge radius of 17Ne to an extended proton configuration with an s;{2} component of about 40%. In 18Ne the smaller radius is due to a significantly smaller s;{2} component. The radii increase again for ;{19-22}Ne due to cluster admixtures.

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The nuclear electric quadrupole moments of the isotopes 26 Na, 27 Na, 28 Na and 29 Na were measured by -NMR spectroscopy in single crystals of LiNbO 3 and NaNO 3 . High degrees of nuclear polarization were produced by optical pumping of the sodium atoms in a fast beam with a collinear laser beam. The polarized nuclei were implanted into the crystals and NMR signals were observed in the -decay asymmetries. Preparatory measurements also yielded improved values for the magnetic moments of 27,31 Na and con rmed the spin I = 3=2 for 31 Na. The results are discussed in comparison with large-basis shell-model calculations.

Nuclear moments of odd-A neon isotopes in the range 17 A 25 have been determined from optical hyperfine structures measured by collinear fast-beam laser spectroscopy. The magnetic dipole moments of 17 Ne, 23 Ne, and 25 Ne, as well as the electric quadrupole moment of 23 Ne, are either reported for the first time or improved considerably. The measurements also decide for a 1/2 + ground state of 25 Ne. The behavior of the magnetic moments of the proton drip-line nucleus 17 Ne and its mirror partner 17 N suggests isospin symmetry. Thus, no clear indication of an anomalous nuclear structure is found for 17 Ne. The magnetic moments of the investigated nuclei are discussed in a shell-model approach.