Studies of light neutron-rich lanthanides at the OSIRIS mass separator facility

This thesis is divided into two parts: Part 1: Nuclide production at OSIRIS describes the OSIRIS electromagnetic on-line separator facility in Studsvik, Sweden. An outline of the production of short-lived neutron-rich nuclides from thermal-neutron induced fission of 235U is given. Special emphasis is put on the two types of ionization modes used in the ANUBIS target/ion source system. The production of molecular ion species in the ion source as well as their advantages and disadvantages are discussed. Some methods to suppress the formation of these species are presented. Part 2: Nuclear structure of the n-rich lanthanides starts with a short background to the large interest in the neutron-rich lanthanides in the mass region A=150-160. The vibrational and rotational aspects of the collective quadrupole deformation model is briefly described, as well as octupole deformation and quasiparticle excitations. The octupole vibrational and two-quasiparticle characteristics of negative-parity bands at low energies in the light n-rich lanthanides are discussed. The use of transition rate systematics as a tool for investigating nuclear structure properties is touched upon. To conclude, different experimental methods used at OSIRIS are briefly described. (62 refs.) (au)