Doctoral Dissertations


Seth Kilby

Keywords and Phrases

Gamma Tomography; Monte-Carlo; Radiography; Transport


”Nondestructive characterization techniques such as gamma tomography represent powerful tools for the analysis and quantification of physical defects and radionuclide concentrations within nuclear fuel forms. Gamma emission tomography, in particular, has the ability to utilize the inherent radiation within spent nuclear fuel to provide users with information about the migration and concentration of fission and activation products within the fuel form. Idaho National Laboratory is interested in using this technology to analyze new nuclear fuel forms for potential use in next generation nuclear reactors. In this work, two aspect of the system are analyzed. The first is a semi-analytic radiation transport methodology in conjunction with a parallel beam collimator developed to facilitate the acquisition of data from Monte-Carlo modeling of a small submersible gamma tomography system, with a focus on emission information. The second is a pinhole collimator designed to optimize count rates, diameter, and acceptance angle to increase the sampling of the fuel forms to decrease data acquisition time. Utilizing the semi-analytical technique, computational savings of 107-1011 can be achieved with a degradation in accuracy of 1845% compared to a standard isotropic uniform Monte-Carlo N Particle transport simulation. However, this loss in accuracy can be minimized by increasing the parallel beam collimator’s aspect ratio where it tends towards a degenerate cylinder. The semianalytic technique is also compared to inbuilt acceleration techniques. The pinhole collimator design yields count rates on the order of 100s-1000s which represents a 101-102 increase in actual count rates over the entirety of the photon spectrum”--Abstract, page iv.


Graham, Joseph T.

Committee Member(s)

Alajo, Ayodeji Babatunde
Liu, Xin (Mining & Nuclear Engr)
Lee, Hyoung-Koo
Hoffman, Andrew


Nuclear Engineering and Radiation Science

Degree Name

Ph. D. in Nuclear Engineering


This material is based upon work supported by the U.S. Department of Energy, Nuclear Energy University Programs, project 17-13011, and by the U.S. Nuclear Regulatory Commission, Nuclear Education Program under award NRC-HQ-13-G-38- 0026.


Missouri University of Science and Technology

Publication Date

Fall 2020

Journal article titles appearing in thesis/dissertation

  • A source biasing and variance reduction technique for Monte Carlo radiation transport modeling of emission tomography problems
  • Comparison of a semi-analytic variance reduction technique to classical Monte Carlo variance reduction techniques for high aspect ratio pencil beam collimators for emission tomography applications
  • Design and optimization of a pinhole collimator for a high-resolution emission gamma ray tomography system


xiii, 120 pages

Note about bibliography

Includes bibliographic references.


© 2020 Seth Michael Kilby, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11790

Electronic OCLC #