Studies of superdeformation in the gadolinium nuclei

We have used the 8π γ-ray spectrometer at the Chalk River TASCC facility to study superdeformed rotational bands in the chain of isotopes 145–149Gd. The five bands already known have been extended to higher spin, while four new excited bands have been discovered. The use of very similar reactions, data-acquisition parameters and data-analysis techniques, combined with the enlarged set of data, has allowed us for the first time to approach the topic of superdeformation in the A = 150 mass region from a comprehensive point of view. Transition energies of neighbouring nuclei were compared to extract effective aligned spins of the added particle. Such a comparison requires knowledge of relative nuclear spins, which we have to assume. Nevertheless, we find that a very illustrative picture emerges making it possible to understand all nine bands in the Gd isotopes within a very simple scheme of orbital assignments.