A Study of the Gamma-Rays Associated with the Inelastic Scattering of Neutrons in Extended Target Samples


The gamma-rays produced’ in the inelastic scattering of 14 MeV neutrons have been studied using a gamma-ray spectrometer employing a sodium iodide scintillation detector. The source neutrons are produced by the T(d,n)"He reaction using the Radiation Centre Dynamitron and.the SAMES accelerator. In order to overcome the large gamma-ray background and large stray neutron signal due to the sensitivity of the sodium iodide detector to neutrons, heavy shielding around the gamma-ray detector is used together with a particle time of flight discrimination system based on the associated particle time of flight method. The instant of production of a source neutron is defined by detecting the associated alpha-particle which enables discrimination between the neutrons and gamma-rays because of their different time of flight times. The electronic system used for measuring the time of flight of the neutrons and gamma-rays over the fixed flight path is described. The materials studied in this work were iron and concrete because of their importance as structural and shielding materials in the construction of both fission and fusion reactors. Several sample thicknesses were studied to determine the multiple scattering effects in large sample. The observed gamma-ray spectra from each sample at several scattering angles in the angular range 0°-90° enabled absolute differential gamma-ray production cross-sections and angular distributions of the resolved gamma-rays from iron to be measured and compared with published data where available. For the concrete sample, the absolute differential gamma-ray production cross-sections for discrete 1 MeV ranges and the angular distributions were measured and compared with cross-sections synthesized from the published cross-section data for the elements constituting concrete. The number of gamma-rays produced from each sample in the angular range studied were compared with the predictions of a theoretical model based on the continuous slowing down model and Fermi-Age equation, Good agreement between experiment and theory is obtained and a single parameter found which describes the effects of multiple scattering in both materials.

Publication DOI: https://doi.org/10.48780/publications.aston.ac.uk.00012021
Divisions: College of Engineering & Physical Sciences
Additional Information: Copyright © Al-Shalabi, 1981. B. Al-Shalabi asserts their moral right to be identified as the author of this thesis. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without appropriate permission or acknowledgement. If you have discovered material in Aston Publications Explorer which is unlawful e.g. breaches copyright, (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please read our Takedown Policy and contact the service immediately.
Institution: Aston University
Uncontrolled Keywords: gamma-rays,inelastic scattering,neutrons,extended target samples
Last Modified: 19 Dec 2023 15:16
Date Deposited: 13 Jan 2011 10:23
Completed Date: 1981
Authors: Al-Shalabi, Bassam A.R.

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