Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.649153
Title: Experiments on the nuclear structure of 168Er and other heavy nuclei
Author: Davidson, Walter Fraser
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1994
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Abstract:
A comprehensive series of radioactive source, accelerator-based and reactor-based experiments to determine the structure of some 40 heavy nuclei beyond mass value 100, especially on the nucleus 168Er, is described in the first two Sections of the thesis. In Section I the results of an extensive measurement programme on 168Er involving (n,γ) and (n,e-) reactions, and single- and two- nucleon transfer reactions, are described. The neutron capture studies were conducted on the curved crystal-, beta-, and pair formation-spectrometers at the High Flux Reactor of the Institut Laue-Langevin, and the particle transfer experiments at the Mcmaster University Tandem Van de Graaff accelerator. The final level scheme deduced from all experiments incorporates the 128 levels identified into 37 rotational bands (for 4 of them, just the bandheads), making 168Er arguably the most fully characterized nucleus known. An IBA model interpretation of the collective states and decay patterns reproduced the observed level scheme well, especially predicting the observed preferred γ-decay from the β- to the γ-band. A discussion is given of various, often competing, theoretical treatments which these experimental results triggered. The results of the large body of particle transfer data from the experiments compared very favourably with the predictions of the Soloviev model. Section II comprises radioactivity studies of isotopes in the actinium chain carried out at the University of Manitoba; in-beam γ-ray spectroscopy of high spin states in rare earth nuclei following (α,xn) reactions performed at the Kernforschungsanlage Jülich cyclotron; and neutron capture studies on heavy nuclei carried out at the Institut Laue-Langevin. Significant advances from the cyclotron experiments included many of the first examples of the "backbending" effect of the nuclear moment of inertia at high spins in nuclei around A=160 and interpretation of observed regularities in the γ-ray spectra in both odd-A and even-A Hg isotopes in terms of the rotational alignment model.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (D.Sc.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.649153  DOI: Not available
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