Exploring nuclear shell structure by laser and beta-NMR spectroscopy
Magda Kowalska (Institut für Physik / CERN)

“Factories” of radioactive isotopes give unique possibilities to study nuclei, i.e. multi-nucleon systems at low energies in extreme conditions: Nuclei with very high or low N/Z ratios and short lifetimes may behave rather differently from what we know about nuclei near the valley of stability.

Our experiment at ISOLDE/CERN uses laser spectroscopy techniques to probe ground state properties of such exotic nuclei. By optically exciting or pumping atoms or ions with laser light (and thanks to the hyperfine interaction of the nucleus with the shell electrons, external magnetic fields or electric crystal fields) we can measure nuclear spins, magnetic dipole and electric quadrupole moments, as well as charge radii.

These data, including most recent highlights: the magnetic moment and spin of ³¹Mg, and the quadrupole moment of the halo nucleus ¹¹Li, are very valuable for exploring nuclear shell structure far from stability or locating regions of deformations and revealing the nature of nuclear halos. The accurate values of nuclear ground-state observables help to test current nuclear models and improve the understanding of strongly interacting systems at the femtometer scale.