Exploring the Exotic Experimental Investigations far from Stability

Doktorsavhandling, 2001

The exploration of exotic nuclei is one of the most intriguing and fastest expanding fields in modern nuclear physics. In the extreme conditions of unsymmetric neutron-proton distributions and small binding energies many nuclear phenomena not encountered closer to stability have revealed themselves, often as a surprise to the nuclear physics community, the prime example being the development of halo structures as the binding energy diminishes. The research in this domain has introduced many new and unexpected phenomena of which a few examples are halo systems, intruder states, soft excitation modes and rare .BETA-delayed particle decays. To comprehend the new features of the nuclear world that are revealed as the drip-lines are approached, reliable and unambiguous experimental data are needed. The work in this thesis summarizes a number of experiments performed along two main lines. An interesting possibility when looking at nuclear structure is the comparisons of mirror nuclei, which in this region are situated on dierent driplines. Three measurements in this this deal with studies of resonances in nitrogen isotopes that are unbound with respect to proton emission. These systems are interesting also as in the studies of proton decay and shell structures far from stability. To study halo systems, longitudinal momentum distributions and cross sections are measured in one-nucleon removal processes where the surviving fragment is detected. Three experiments of this type are reported in this thesis.