Search

The structure of neutron-rich light nuclei around N= 20 and 28 has been investigated at GANIL by means of in-beam gamma-spectroscopy using fragmentation reactions of 36S and 48Ca beams on a Be target. Gamma-decay of relatively high-lying excited states have been measured for the first time in nuclei around 32Mg and 44S. Level schemes are proposed and discussed for a large number of these neutron-rich nuclei around N= 20 and N= 28.

Following mass measurements in the region N= 20 and N= 28, we have studied inelastic nuclear scattering for the nuclei 34Si, 33Al and 32Mg. No evidence for a low-lying shape isomeric 0+state was found in 34Si, and an upper limit for the population cross-section could be established, rendering its existence very unlikely. A new transition was found in 33Al, that is a good candidate for a 2p-2h state and therefore a determination of the 2p-2h gap at N= 20. Inelastic nuclear scattering strongly excites 3-states, as seen in 34Si. A strong transition was found in 32Mg that should correspond to the first 3-in this nucleus, lying very low as compared to theory and systematics in this region.

Proton elastic and inelastic scattering to the first excited state of 6He have been measured over a wide angular range using a 40.9A MeV 6He beam. The data have been analyzed with a fully microscopic model of proton–nucleus scattering using 6He wave functions generated from large space shell model calculations. The inelastic scattering data show a remarkable sensitivity to the halo structure of 6He.