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Neutron And Photon Imaging Capabilities Of Bismuth-Loaded Plastic, Andrew W. Decker
Neutron And Photon Imaging Capabilities Of Bismuth-Loaded Plastic, Andrew W. Decker
Doctoral Dissertations
Plastic scintillators utilizing iridium complex fluorophores offer substantial improvements in light yield, and their light yield is not significantly quenched in compositions with bismuth metalorganic loading at 21% weight. These advances may resolve significant capability gaps for low-cost, portable, and durable dual-particle imaging (DPI) systems for nuclear safety, security, and safeguard purposes. However, all candidate materials should first undergo investigation utilizing industry standards to quantify and evaluate their capabilities. As such, a 21% bismuth-loaded polyvinyl toluene (BiPVT) scintillator fabricated by Lawrence Livermore National Laboratory (LLNL) is computationally and experimentally evaluated as a small, pixelated radiographic array, with individual pixel dimensions …
The Development Of A Parameterized Scatter Removal Algorithm For Nuclear Materials Identification System Imaging, Brandon Robert Grogan
The Development Of A Parameterized Scatter Removal Algorithm For Nuclear Materials Identification System Imaging, Brandon Robert Grogan
Doctoral Dissertations
This dissertation presents a novel method for removing scattering effects from Nuclear Materials Identification System (NMIS) imaging. The NMIS uses fast neutron radiography to generate images of the internal structure of objects non-intrusively. If the correct attenuation through the object is measured, the positions and macroscopic cross-sections of features inside the object can be determined. The cross sections can then be used to identify the materials and a 3D map of the interior of the object can be reconstructed. Unfortunately, the measured attenuation values are always too low because scattered neutrons contribute to the unattenuated neutron signal. Previous efforts to …