Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.659757
Title: Searches for proton radioactivity from highly-deformed nuclei
Author: Munro, Peter
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 2006
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
Abstract:
Proton radioactivity from the highly neutron-deficient nuclide 135Tb has been identified using a new double-sided silicon strip detector (DSSD) system at the Fragment Mass Analyser at Argonne National Laboratory. The decay occurs with an energy of Eρ=1179(7)keV and a half-life t1/2=940+320-220μs. 135Tb was produced via the bombardment of a 92Mo target with a 315MeV 50Cr beam, and is the first proton emitter to be detected from a (p6n) evaporation channel in heavy ion fusion-evaporation reactions. Proton decay rate calculations suggest that this nuclide has a large prolate deformation, in agreement with the predictions of the Möller-Nix mass model and the experimental observations of the neighbouring odd-even lanthanide proton emitters 131Eu and 141Ho. An unsuccessful search for the potential proton emitters 125,126Pm, using the (p6n) and (p5n) evaporation channels respectively, is also reported. The non-observation of 126Pm is consistent with mass model QP predictions, but the non-observation of proton emission from 125Pm suggests a QP value significantly higher than predictions (so that the decay occurs too quickly to be observable) or significantly lower (so that proton emission is not competitive with β decay), or places an upper limit on the production cross-section of this nucleus. The QP predictions of the Möller-Nix and Liran-Zeldes mass models are compared with the currently available data set of experimentally-derived QP values for proton-unbound nuclei in the region of observed proton radioactivity (51≤Z≤83). Both models are found to perform reasonably well and provide useful predictions in this extremely neutron-deficient region.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.659757  DOI: Not available
Share: