Studies of neutron-rich nuclei close to magicity

This thesis deals with the experimental study of exotic neutron-rich nuclei. Three N~20 nuclei close to the so-called island of inversion have been studied via beta decay at the ISOLDE facility at CERN. The low energy level scheme of ³⁴Si (N=20) has been confirmed and the first level schemes for ³⁵Si (N=21) and ³³Mg (N=21) have been proposed. Single particle energies for ³⁵Si have been determined according to which the effective interaction in the sd-fp shell-model has been modified and comparison between theory and experiment is given for different neutron-rich isotopes. The ground state of ³³3Mg has been assigned as Jπ3/2⁺, manifesting the inversion of states in the island of inversion. In addition, superasymmetric fission yields have been obtained for 30 MeV proton induced fission of ²³⁸U at the IGISOL mass separator facility at the Accelerator Laboratory of the University of Jyväskylä. A velocity filter has been designed and built in connection with the IGISOL beam line in order to separate double charged ions