\"The purpose of this work is to study a component of a submersible gamma-ray computed tomography (CT) system used in the non-destructive testing of irradiated nuclear fuels. The first section of this study proposes two acceleration approaches for rapidly modeling a transmission-type gamma-ray tomography system. The first relies on Monte Carlo simulations with a monodirectionally biased source sampled from a sub-volume of the whole source volume. This method estimates the real count rate using analytical correction factors. The second way of acceleration is based on deterministic calculations that use the Beer-Lambert law and detector response characteristics. It shows that both results qualitatively agree with the analog result and can cut computational costs by several orders of magnitude. The second section of this study presents a novel approach for differentiating low-intensity, high-energy gamma rays in high-intensity, lower-energy backgrounds, particularly when the source is in a substantially scattering medium. Using a fast plastic scintillator and pulse-height discrimination, high-energy rays from low-activity 60Co are differentiated from lower-energy rays of high-activity 137Cs. By optimizing the discriminator voltage, the count time required to reach the limit of quantification (LOQ) is significantly reduced. This cost-effective solution utilizes commonly available lab equipment and improves detection efficiency\"-- Abstract, p. iv
","abstract_html":"<p>"The purpose of this work is to study a component of a submersible gamma-ray computed tomography (CT) system used in the non-destructive testing of irradiated nuclear fuels. The first section of this study proposes two acceleration approaches for rapidly modeling a transmission-type gamma-ray tomography system. The first relies on Monte Carlo simulations with a monodirectionally biased source sampled from a sub-volume of the whole source volume. This method estimates the real count rate using analytical correction factors. The second way of acceleration is based on deterministic calculations that use the Beer-Lambert law and detector response characteristics. It shows that both results qualitatively agree with the analog result and can cut computational costs by several orders of magnitude. The second section of this study presents a novel approach for differentiating low-intensity, high-energy gamma rays in high-intensity, lower-energy backgrounds, particularly when the source is in a substantially scattering medium. Using a fast plastic scintillator and pulse-height discrimination, high-energy rays from low-activity <sup>60</sup>Co are differentiated from lower-energy rays of high-activity <sup>137</sup>Cs. By optimizing the discriminator voltage, the count time required to reach the limit of quantification (LOQ) is significantly reduced. This cost-effective solution utilizes commonly available lab equipment and improves detection efficiency"-- Abstract, p. iv</p>","abstract_has_math":false,"creators":["Jin, Zhongmin"],"institution":"Missouri University of Science and Technology","degree_name":"Ph. D. in Nuclear Engineering","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":null,"date_issued":"","date_published":null,"updated_at":"2026-07-24T03:18:26Z","subjects":["Gamma-ray tomography","monte carlo","non-destructive testing","nuclear fuel","plastic scintillator","radiation transport","Engineering","Nuclear Engineering"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsmine.mst.edu/doctoral_dissertations/3292","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Jin, Zhongmin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:type","label":"Dc Type","values":["Dissertation - Open Access"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. D. in Nuclear Engineering"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Missouri University of Science and Technology"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Gamma-ray tomography","monte carlo","non-destructive testing","nuclear fuel","plastic scintillator","radiation transport","Engineering","Nuclear Engineering"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsmine.mst.edu/doctoral_dissertations/3292"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["\"The purpose of this work is to study a component of a submersible gamma-ray computed tomography (CT) system used in the non-destructive testing of irradiated nuclear fuels. The first section of this study proposes two acceleration approaches for rapidly modeling a transmission-type gamma-ray tomography system. The first relies on Monte Carlo simulations with a monodirectionally biased source sampled from a sub-volume of the whole source volume. This method estimates the real count rate using analytical correction factors. The second way of acceleration is based on deterministic calculations that use the Beer-Lambert law and detector response characteristics. It shows that both results qualitatively agree with the analog result and can cut computational costs by several orders of magnitude. The second section of this study presents a novel approach for differentiating low-intensity, high-energy gamma rays in high-intensity, lower-energy backgrounds, particularly when the source is in a substantially scattering medium. Using a fast plastic scintillator and pulse-height discrimination, high-energy rays from low-activity 60Co are differentiated from lower-energy rays of high-activity 137Cs. By optimizing the discriminator voltage, the count time required to reach the limit of quantification (LOQ) is significantly reduced. This cost-effective solution utilizes commonly available lab equipment and improves detection efficiency\"-- Abstract, p. iv
"]},{"key":"dc:title","label":"Title","values":["Characterization of the Acquisition Parameters of a Submersible Gamma-Ray Computed Tomography System"]}]}],"canonical_facts":{"dc:creator":["Jin, Zhongmin"],"dc:description.abstract":["\"The purpose of this work is to study a component of a submersible gamma-ray computed tomography (CT) system used in the non-destructive testing of irradiated nuclear fuels. The first section of this study proposes two acceleration approaches for rapidly modeling a transmission-type gamma-ray tomography system. The first relies on Monte Carlo simulations with a monodirectionally biased source sampled from a sub-volume of the whole source volume. This method estimates the real count rate using analytical correction factors. The second way of acceleration is based on deterministic calculations that use the Beer-Lambert law and detector response characteristics. It shows that both results qualitatively agree with the analog result and can cut computational costs by several orders of magnitude. The second section of this study presents a novel approach for differentiating low-intensity, high-energy gamma rays in high-intensity, lower-energy backgrounds, particularly when the source is in a substantially scattering medium. Using a fast plastic scintillator and pulse-height discrimination, high-energy rays from low-activity 60Co are differentiated from lower-energy rays of high-activity 137Cs. By optimizing the discriminator voltage, the count time required to reach the limit of quantification (LOQ) is significantly reduced. This cost-effective solution utilizes commonly available lab equipment and improves detection efficiency\"-- Abstract, p. iv
"],"dc:identifier":["https://scholarsmine.mst.edu/doctoral_dissertations/3292"],"dc:subject":["Gamma-ray tomography","monte carlo","non-destructive testing","nuclear fuel","plastic scintillator","radiation transport","Engineering","Nuclear Engineering"],"dc:title":["Characterization of the Acquisition Parameters of a Submersible Gamma-Ray Computed Tomography System"],"dc:type":["Dissertation - Open Access"],"thesis:degree_name":["Ph. D. in Nuclear Engineering"],"thesis:institution_name":["Missouri University of Science and Technology"]},"updated_at":"2026-07-24T03:18:26Z"}