J.S. Feener, “Fluorescence Imaging for Nuclear Arms Control Verification”, Ph.D. Dissertation, Nuclear Engineering, Texas A&M University, College Station, TX (2014).
Nuclear disarmament is a highly debated subject. Proponents argue that political conditions for nuclear disarmament are ripe. Opponents reason that dismantlement could create instability leading to a higher probability of nuclear war or large-scale conventional war. Verification of disarmament can help alleviate instabilities and as nuclear arsenals decrease, verifying actual warheads and not just delivery vehicles will become more important. Current techniques that could be used in warhead verification have the ability to reveal sensitive information about the warhead and thus require an information barrier.
This research developed a proof-of-principle concept for a new technique to address the need of nuclear warhead verification for arms control treaties. Specifically, this technique uses fluorescence imaging to determine fissile material attributes in verifying an uncanned nuclear warhead or warhead component without revealing sensitive information. This could potentially reduce the need for an information barrier.
Experiments were performed using a Princeton Instruments PIXIS: 1024B/BVU back-illuminated CCD camera to image the fluorescence produced by the decay of nuclear material. The Monte Carlo simulation tool GEANT4 was used to model the experimental setups and to compare with the experimental results. The results verified the proof-of-concept of fluorescence imaging for use in nuclear arms control treaty verification.
Fluorescence imaging would be most beneficial to the fissile material attributes of U enrichment (greater than a threshold) and symmetry. It also contributes valuable data to verifying the presence of fissile material, presence of Pu, presence of U, mass greater than a threshold, Pu age, and 239Pu to 240Pu ratio greater than a threshold. Fluorescence imaging may also be beneficial to the absence of oxide attribute but additional experiments are needed to confirm this assumption. Additionally, it was concluded that the only potential for revealing presumably sensitive information is the ability to provide too much image detail on external surfaces of Pu components. However, simple steps can be taken to prevent the imaging system from acquiring too much detail; thus eliminating the need for an information barrier.