Ground state moments and spins of neutron-rich K and Al isotopes as probes for changes in nuclear structure

This contribution focusses on recent measurements of nuclear moments and spins using two complementary methods. The ground state magnetic moments and spins of the exotic isotopes ^49,51K have been measured at the ISOLDE facility at CERN using bunched-beam high-resolution collinear laser spectroscopy. The re-inversion of the ground state spin from I = 1/2 in ^47,49K back to the normal I = 3/2 in ⁵¹K has been established. At GANIL (Caen, France) the quadrupole moment of the ³³Al ground state has been measured using the continuous-beam β-nuclear magnetic resonance method applied to a spin-polarized beam produced at the LISE fragment separator. The large value establishes a very mixed wave function with about equal amounts of normal and neutron particle-hole excited configurations contributing to its ground state wave function. This illustrates the transitional nature of isotopes at the border of the island-of-inversion.