Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"special nuclear material"”.
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Modeling special nuclear material diversion from a pyroprocessing facility
… fuel cycle implemented in the US, used nuclear fuel (UNF) steadily increases. One proposed solution is the transition to a closed nuclear fuel cycle, in which reprocessing reduces build up of UNF. Pyroprocessing is an attractive method for this transition for its capabilities separating …
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Dual Neutral Particle Beam Interrogation of Intermodal Shipping Containers for Special Nuclear Material
… provide an avenue to smuggle unsecured or stolen special nuclear material (SNM). The only direct method fielded to indicate the presence of SNM is by passive photon/neutron radiation detection. Active interrogation using neutral particle beams to induce fission in SNM is a method under …
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Using a superconducting cyclotron to detect special nuclear material through multiple monoenergetic gamma radiography and o-axis photon scattering/
… and measure o-axis photon scattering to nd special nuclear material (SNM). The cyclotron is a small enough accelerator to be a viable option for scanning commercial cargo containers at maritime ports, airports, rail crossings, and other places of interest. This research presents a technique …
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Imaging the ionization track of alpha recoils for the directional detection of weapons grade plutonium
Since the dawn of the nuclear weapons era, political, military, and scientific leaders around the world have been working to contain the proliferation of Special Nuclear Material and explosively fissile material. This paper describes the construction of a prototype, directional, fast neutron …
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Monte Carlo Method for Calorimetric NRF Cargo Screening
A number of fields in nuclear security require isotopic analysis and identification. Nuclear resonance fluorescence(NRF) has provided a non-intrusive isotope-sensitive measurement technique to detect special nuclear material in cargo [8], and has been proposed to be used as a verification technique …
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Compact neutron sources for zero knowledge warhead verification via epithermal neutron transmission analysis
… and minimize the security risk of transporting special nuclear material to dedicated verification facilities. Experimental results demonstrate the feasibility of a tomographic approach to zero-knowledge physical cryptography, and MC simulations offer promising results for compact epithermal …
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A novel detection system using neutron/gamma pulse shape discrimination, for use in active interrogation environments
… improvements are being sought to identify special nuclear material more accurately. Active interrogation is a current field of research for this application, capable of penetrating shielding materials but which can feature a complex and challenging radiation field for detectors to operate …
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Automated isotope identification algorithms for low-resolution gamma spectrometers
… identifiers (RIIDs) are widely deployed for nuclear security applications, but these detectors generally have poor isotope identification performance. Most of these deployed detectors use low-resolution NaI scintillators due to their low cost and good efficiency. Alternative detection …
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Characterization of fissile material using low energy neutron interrogation
… methods for detecting and interdicting illicit nuclear trafficking has resulted in the exploration of various methods for active neutron interrogation, specifically for the presence of special nuclear material (SNM) in cargo containers. The proposed system aims to defeat the ability of …
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Reconstruction of urban radiation landscape using machine learning methods
… task includes identifying illicit movement of special nuclear material, locating unusual radioactive events, and estimating the intensity of radioactive sources to name a few. Besides those anomalous radiation sources, there is naturally occurring radioactive material presented in air, soil and …
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Neutron Response Vectorization and Optimization of Moderating Neutron Spectrometers for Active Interrogation
The detection of special nuclear material (SNM) is no trivial task; the low activity of isotopes such as 235U and the ease of shielding make their passive detection virtually impossible in the maritime environment. Active interrogation, while increasing the radiative signature, also increases the …
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Remote detection of fissile material : Cherenkov counters for gamma detection
… and to detect, identify, and characterize special nuclear material (SNM) through the gamma rays and neutrons emitted. Long-range applications require detectors with a large solid angle and an ability to significantly suppress lowenergy background from linear electron accelerators. Water …
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A novel low-dose approach to active detection of shielded high-Z materials
… gamma lines produced from low threshold, high-Q nuclear reactions can be used to detect the presence of high-Z material shielded in low- and medium-Z cargo. Specifically, this work establishes a research foundation to inform the eventual development and optimization of a new type of low-dose, …
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Neutron Resonance Transmission Analysis of Nuclear Material Using a Portable D-T Neutron Generator
The accurate identification and quantification of nuclear material is important for nuclear security, nonproliferation, and safeguards missions. Existing techniques have limitations in terms of their isotopic specificity, isotopic range, and their capacity to analyze thick or shielded targets. …
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Analysis of the optical coupling of wavelength-shifting fibers to organic liquid scintillator filled fluoropolymer tubes for industrial and nuclear security applications
Industrial and nuclear security applications continue to push radiation detection development into new and exciting frontiers. In this work, an innovative detection module is developed and tested for use in a cosmic ray imaging (CRI) system designed for oil field characterization and is evaluated …
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Tritium Matters: Constructing Nuclearity and Navigating Ambivalence of a Unique Material
… Each phase is characterized by a dominant "nuclearity" and situated in context of "nuclear exceptionalism" (Hecht 2014) that directly and indirectly affects material conditions, elite decision-making, and radiological impacts on the environment and human health. Because it is pervasive, …