Doctoral Dissertations

Keywords and Phrases

Gamma-ray tomography; monte carlo; non-destructive testing; nuclear fuel; plastic scintillator; radiation transport


"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


Graham, Joseph T.

Committee Member(s)

Alajo, Ayodeji Babatund
Castano Giraldo, Carlos Henry
Alam, Syed B.
Okoronkwo, Monday Uchenna


Nuclear Engineering and Radiation Science

Degree Name

Ph. D. in Nuclear Engineering


Missouri University of Science and Technology

Publication Date

Spring 2024


xi, 84 pages

Note about bibliography

Includes_bibliographical_references_(pages 72-83)


© 2023 Zhongmin Jin, All rights reserved

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 12336

Electronic OCLC #