RECENT RESULTS FROM BETA-DECAY STUDIES OF NEUTRON-RICH Rb ISOTOPES PRODUCED AT ISAC USING A UC_X TARGET

摘要

Recent experiments to investigate the properties of photon-induced fission for ~(234,238)u as well as ~(232)Th were carried out at the superconducting Darmstadt electron linear accelerator S-DALINAC [1]. The neutron-rich Strontium and Zirconium nuclei around A = 100 display an unusually fast transition of ground-state shape at the N=60 neutron sub-shell closure. In these nuclei the change between a nearly spherical shape to a strongly prolate, rigid deformation occurs by the addition of just one or two nucleons, or by a few tens of keV excitation energy. The states associated with these nuclear states can mix and all observable quantities such as excitation energy and transition rates are modified. In addition, the relative intensities between transitions from an excited state with very different energies can make it difficult to observe weak transitions even if their transition strength is large. These transitions and transition strength can be very important in correctly interpreting the underlying structure.