Study of exotic nuclei at ISOLDE (Kontingent til ISOLDE)

Nuclear structure studies have been limited to stable or near stable isotopes in the past. The availability of radioactive ion beams (RIB) enlarges the scope of such studies considerably as exotic nuclei far from stabilty become accessible for the first t ime. The Norwegian nuclear chemists played an important/leading role in the beginning of ISOLDE. The ISOLDE facility at CERN has a long history of producing radioactive ions. The acceleration of these ions with the REX accelerator offers unique possibilit ies and makes ISOLDE the facility with the widest variety of RIB world wide. The world-leading role of ISOLDE will be strengthened in the future with an energy and intensity upgrade (HIE-ISOLDE). The scientific subject of the proposed project is the shell structure of nuclei far from stability and, closely related to that, the development of nuclear shapes and shape coexistence. The Nuclear Physics group from Oslo has been involved in several experiments at REX-ISOLDE the last six years as part of collab orations led by other institutions. In 2009 we propose to start our own research program to study the structure of exotic nuclei at ISOLDE by gamma-ray spectroscopy after Coulomb excitation using the MINIBALL array of segmented germanium detectors. The a ccepted Oslo-lead proposal to study shapes in neutron-deficient rare earth isotopes, is expected to get its first beam time during 2012. These experiments are expected to provide excellent data for a couple of PhD thesis and give several scientific public ations. A PhD student from Oslo (G.Tveten) was based at CERN-ISOLDE for two years, working on a design study for a spectrometer for HIE-ISOLDE. After the upgrade to HIE-ISOLDE we also plan to look at transfer reactions and extend the research program don e on stable nuclei in Oslo, to exotic nuclei at HIE-ISOLDE. The nuclear theory group at the University of Oslo plays a vital role in the Norwegian ISOLDE project.