Universität zu Köln

Armstrong, Michael (2024). Spectroscopy of Excited States of 130Cd and Simulations and Detector Developments for HISPEC Slowed Down Beam Experiments. PhD thesis, Universität zu Köln.

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Abstract

In this doctoral thesis, new experimental findings on the nuclear structure of 130Cd and simulations for the HISPEC slowed down beam (SDB) campaign are presented. In this work 131In and 130Cd are investigated in an inflight-decay spectroscopy experiment performed at the RIKEN RIBF facility. 131In and 130Cd were produced in fragmentation fission reactions and proton knockout reactions with 9Be targets and were identified in the BigRIPS and ZeroDegee spectrometers. The excitation energies and half-lives of excited nuclear states populated in proton knockout reactions were inferred from the energies of gamma-rays emitted in their decays. This was achieved by comparing the energies of gamma-rays detected in the HiCARI array to Monte-carlo simulations. Two new gamma-decays were observed in 130Cd which were attributed to two previously unobserved excited states. These results were interpreted in the context of a nuclear shell model calculation which was shown to successfully describe the structure of 130Cd including the newly observed states. Simulations of the HISPEC SDB campaign, proposed to study the nuclear structure of rare-isotope beams produced in the SuperFRS at FAIR with AGATA, were produced. The transport of 64Ni through the SuperFRS and its slowing from 233 MeV/u to the Coulomb barrier in a 27Al degrader was simulated using the MOCADI ion-transport code. The kinematic reconstruction and identification of ions after the degrader was simulated in a Geant4 simulation of the proposed SDB setup. The performance, positioning and geometry of SDB detectors, required for the identification of ions and the reconstruction of the energies of gamma-rays emitted in the gamma-decay of ions excited in Coulomb excitations with a thin 197Au target, was evaluated. SDB experiments with the proposed setup were found to be feasible under the conditions identified as required of SDB detectors for experiments lasting five days with at least 10^4 p/s available 64Ni beam intensity.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Armstrong, Michael armstrongmig@outlook.com UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-731455
Date:	31 May 2024
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institute for Nuclear Physics
Subjects:	Physics
Uncontrolled Keywords:	Keywords Language Physics UNSPECIFIED Nuclear Structure UNSPECIFIED Simulations UNSPECIFIED
Date of oral exam:	12 April 2024
Referee:	Name Academic Title Jolie, Jan Professor
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/73145