The detection of illicit weapons-grade nuclear material is a significant technical challenge receiving a great deal of attention in the nuclear community. A proposed solution is to actively bombard the I would like to offer Dr. Jennifer J. Ressler my sincere gratitude, for without her this research would not have been possible. From bringing me onto her team, arranging the funding that supported this work, revising my documents, to answering countless questions, she has been immensely helpful. Equally deserving of special recognition is Dr. Todd S. Palmer, who has served as my adviser for the past five years. Dr. Palmer has given me the inspiration, guidance, motivation, and professional advice I needed in order to be successful both academically and professionally. I would also like to recognize Dr. David M. Hamby, whose engaging teaching style and course materials were invaluable to the research performed for this thesis.