Nuclear spin alignment and static moments of light projectile fragments measured with the Level Mixing Resonance (LMR) method

We report on the first Level Mixing Resonance experiments performed on β-decaying nuclei produced and aligned in intermediate energy fragmentation reactions. From the resonant change of the β-asymmetry as a function of a static magnetic field, we derived information on the initial alignment of 12B and 18N projectile fragments and on the nuclear structure of the neutron 18N nucleus. Positive alignments ranging from 0.9% to 14.4% have been found for different cuts in the longitudinal momentum distribution of 12B and 18N fragments. A very large ratio for the quadrupole frequency to the magnetic moment has been measured for the neutron rich 18N fragments.