New analytical techniques for the investigation of alpha clustering in nuclei

[摘要] This thesis presents the analysis of two experiments, one measuring the He-4(N-14,a) and He-4(N-14,d)O-16 reactions and a second measuring the He-4(Ca-40,a), He-4(Ca-44,a) and He-4(Ca-48,a) reactions. These measurements were used to investigate F-18 and Ti-(44,48,52) respectively. In both experiments the Thick Target Inverse Kinematics technique was used and the analysis focused on the investigation of alpha-clustering. The measurements of He-4(N-14,a) and He-4(N-14,d)O-16 were performed between Ex[F-18] = 5.5 – 16 MeV, and evaluated using a full R-matrix analysis up to 9 MeV. From this nine new states in F-18 were extracted and the alpha-cluster structure of F-18 was explored by comparison with nuclear models. The measurements of He-4(Ca-40,a), He-4(Ca-44,a) and He-4(Ca-48,a) were made over the ranges Ex[T-44] = 9 – 17 MeV, Ex[Ti-48] = 13.5 – 24 MeV and Ex[Ti-52] = 12 – 20 MeV. The experimental data were analysed using a novel technique developed in this thesis for the identification of fragmented alpha-clustered states, known as the spectral signature analysis. From this analysis nine such states were identified in Ti-44, in good agreement with previous work. None were identified in Ti-48 and three in Ti-52. The implications of these results for alpha-clustering in the fp-shell are discussed.

[发布机构] University:University of Birmingham;Department:School of Physics and Astronomy

[关键词] Q Science;QC Physics