Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.725191
Title: Structure of ²⁵Na measured using d(²⁴Na,p)²⁵Na with a radioactive ²⁴Na beam
Author: Knapton, Andrew J.
ISNI:       0000 0004 6422 8442
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 2017
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Abstract:
The structure of 25Na is studied using the (d, p) transfer reaction using the ISAC-II accelerator at TRIUMF, Canada. An 8 MeV per nucleon beam of 24Na, incident onto a 1.0 mg CD2 target was used to populate excited states in 25Na. The target was surrounded by the SHARC and TIGRESS arrays, which were used to detect the ejected protons, and coincident gamma-rays emitted from the excited 25Na nuclei respectively. The angular distribution of the protons has been analysed for each state observed and compared to the theoretical distributions generated using TWOFNR to get a value of the spectroscopic factors. Data were compared to WBC shell-model calculations in order to assign spin and parities to each observed state. States at 2.788 MeV and 3.455 MeV are strongly populated and show a strong s-wave contribution to the wave functions. In addition, the structure of the astrophysically relevant mirror nucleus 25Si is commented on. The reaction 24Al(p, gamma)25Si reaction is thought to occur in hot stellar environments, but little to no experimental data exist that confirm reaction rates calculated for this reaction. The spectroscopic factors found in this work for 25Na are used as a point of comparison and used to determine the validity of theoretical reaction rate calculations used for the astrophysical reaction. The relevant energy region in the reaction 24Al(p, gamma)25Si is between the proton separation energy of 3.414 and 4 MeV. Two states are observed in this energy range in 25Na at 3.455 and 3.995 MeV, though the 3.455 MeV state is expected to be Thomas-Ehrman shifted below the 3.414 MeV threshold in the mirror 25Si. The state at 3.995 MeV was found to have an s-wave component that matched the predicted value from literature. No other states were observed within the relevant energy region in 25Na.
Supervisor: Catford, Wilton Sponsor: STFC
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.725191  DOI: Not available
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