Spectroscopy of neutron deficient mass A=130 nuclei

Medium and high spin states have been populated and studied in the very neutron deficient 127Pr, 131Pm and 133Sm nuclei. The isotopes 127Pr and 131Pm are the lightest Pr and Pm nuclei studied to date, and the behaviour of these two nuclei has changed our view on the role of the h11/2 neutrons and protons in the alignment processes within these nuclei. Comparisons of these nuclei with standard calculations and with extended calculations are discussed along with comparisons with heavier Pm and Pr nuclei. It has been found necessary to use extended Cranked Shell Model calculations to accurately reproduce the light mass 130 nuclei; this study also reveals that, while the standard calculations appear to adequately reproduce the behaviour of the heavier isotopes, they may do so for the wrong reasons. The extended calculations have been applied to the 133Sm nucleus for the first time in an attempt to address some of the problems encountered in earlier work. In doing so we have found that, although the extended calculations perform far better than standard calculations, some aspects of their predictions fail when applied to some of the states within 133Sm. In a separate experiment using the EUROBALL array, excited states have been populated and studied in 127La. We have been able to extend all of the known structures within this nucleus by several transitions, and one of the bands (band 2) has been interpreted as a smooth terminating band. This is the first observation of such a structure in valence space. Although this band is not observed to termination, due to insufficient statistics, we are able to show, by comparison with cranked Nilsson calculations that this band is based upon a π[(g7/2d5/2)5(h11/2)2] x ν[(g7/2d5/2)12(h11/2)6(d3/2s1/2)2] configuration, which can accommodate spin up to 47.5 h/2π, and points to the first observation of a smooth terminating structure outside the mass A=110 region. (author)