Probing single-particle and collective states in atomic nuclei with Coulomb excitation

University dissertation from Dept. of Physics, Lund University

Abstract: A series of experiments and developments, related to stable and radioactive isotopes, have been carried out. These studies have focused on measuring the low-lying excitations of spherical and deformed nuclei using electromagnetic (Coulomb) excitation and also on developments in detector technology for upcoming radioactive ion beams facilities. The low-lying excitations in the nuclei 107,109Sn and 107In have been investigated using low-energy Coulomb excitation at the REX-ISOLDE facility at CERN. The measured reduced transition probabilities were compared to predictions of nuclear structure models. In addition, a relativistic Coulomb excitation experiment was carried out using the FRS at GSI with the nucleus 104Sn. These radioactive ion beam experiments provide important constraints for large-scale-shell-model calculations in the region of the doubly magic nucleus 100Sn. A stable Coulomb excitation experiment was also carried out in order to explore the properties of low-lying structures in the nucleus 170Er. These measurements resulted in new data for the reduced transition matrix elements in this nucleus. The results were compared to predictions of models of deformed nuclei. The last study contained in this work is related to the design of a new detector system, to be deployed at the upcoming radioactive ion beam facility FAIR. A prototype of the detector was tested with a 180 MeV proton beam and the results were compared to Geant4 simulations. The results highlight important constraints for the design of the full detector system.

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