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 20 of 28 for “"neutron sources"”.
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Mobile neutron sources for residual stress measurement
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1994.
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Reconsideration of Inherent Neutron Sources in Liquid Fuel of Molten Salt Reactors
Calculation of inherent neutron sources from alpha-n and gamma-n reactions in molten fluoride fuel salts using current gamma-n and alpha-n cross-sections and codes where possible. Original inherent neutron source was calculated for Molten Salt Reactor Experiment (MSRE) in 1959 using then-determined …
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Monte Carlo Simulations of Powder Diffraction at Time-of-Flight Neutron Sources
… McStas software, are used for the simulation of neutron diffraction at the SMARTS (Spectrometer for Materials Research at Temperature and Stress) diffractometer in the Los Alamos Neutron Science Center. The simulations include all the instrumental components, such as the moderator, guide system, …
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Compact neutron sources for zero knowledge warhead verification via epithermal neutron transmission analysis
… during measurement. Compact epithermal neutron sources enable the verification process to occur on-site and minimize the security risk of transporting special nuclear material to dedicated verification facilities. Experimental results demonstrate the feasibility of a tomographic approach …
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Compact neutron sources for Nuclear Physics: from accelerator-based to laser-driven neutron beams
Pulsed neutron beams are a valuable tool in nuclear physics with applications in a wide variety of fields, including fission and fusion, astrophysics, homeland security, medicine, cultural heritage, avionics, and other industrial or research applications. Despite the potential use of neutron beams, …
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Monte Carlo calculation and analysis of neutron and gamma fields at spallation neutron sources for simulating cosmic radiation
The research of the neutron induced Single Event Effect (SEE) at aircraft altitudes or at ground level are very important since the neutron radiation is able to cause serious errors or damages on electronic components and system. TheWeapons Neutron Research (WNR) facility at Los Alamos Neutron …
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A combined radiographic and time-of-flight method for zero-knowledge warhead verification
… uses time-structured beams of epithermal neutrons to verify weapon isotopics and geometry without creating or transmitting meaningful information about the device design. This method seeks to remedy information security and hoax resistance issues inherent in previously proposed …
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In vivo boron-10 analysis for the pre-screening of compounds for BNCS
… for the pre-screening of compounds for Boron Neutron Capture Synovectomy (BNCS). Three approaches were investigated: emission computed tomography (ECT), transmission computed tomography (TCT) and in vivo prompt gamma neutron activation analysis (IVPGNAA). Each was first studied using …
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Capabilities and limitations of Phase Contrast Imaging techniques with X-rays and neutrons
… all the more important since coherent X-ray and Neutron sources are mostly unavailable. We develop a model for PCI contribution to imaging for partially incoherent systems, and develop a methodology to identify a minimum and an optimum coherence length 4min and opt. We propose a figure-of-merit …
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Experimental determination of the buckling for unusual geometrical shapes using paraffin
The buckling constant for neutron moderators in the shape of an elliptic cylinder, hemisphere, and"piggy-back" cylinder has been determined by experimental measurements using paraffin as a moderator. The pulsed neutron sources technique was used throughout the work; a fast neutron burst of short …
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A Bf3 Fast Neutron Dosimeter (Long Counter)
A BF3 fast neutron dosimeter or long counter is constructed and calibrated for use with the Cockcroft-Walton accelerator and UTR-IO reactor at Virginia Polytechnic Institute. The counter consists of a paraffin cylinder 8 inches in diameter, having a BF3 proportional detector on the axis and a set …
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Characterization of neutron fields around an intense neutron generator
Neutron fields in the vicinity of the University of Ontario Institute of Technology neutron facility have been investigated in a series of simulations and experiments. The neutron fluence at several locations around the neutron generator facility has been simulated using MCNPX 2.7E Monte Carlo …
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Design of a Multiloop Pyroelectric Neutron Generator Control System
Pyroelectric neutron generators are compact, low power systems which may be capable of producing short intense pulses of neutrons from D-D fusion reactions. Initial analysis of pyrofusion dynamics has indicated the potential to manipulate the pulse characteristics through system control. This …
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Transmutation rates in the annulus gas of pressure tube water reactors
… Since fuel bundles are continuously under high neutron fluxes, annulus gas nuclides undergo different nuclear transformations generating new composition of the gas that might have different physical properties which are undesirable for the annulus system. In addition, gas nuclides become …
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Advanced brachytherapy dosimetric considerations
… shielding considerations for both photon- and neutron-emitting radionuclides. Monte Carlo simulation methods were employed to calculate dose distributions for virtual and commercial brachytherapy sources. Radionuclides studied were 103Pd, 1251, 131Cs, 137Cs, 169b, 192Ir, and 252Cf. 252Cf …
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Imaging the ionization track of alpha recoils for the directional detection of weapons grade plutonium
… construction of a prototype, directional, fast neutron detector, modeled after the Dark Matter Time Projection Chamber. Fast neutrons are emitted by a host of interesting sources, including medical isotopes, research sources, cosmic neutron spallation, and the most interesting, SNM and WGP. This …
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CENTRIFUGALLY TENSIONED METASTABLE FLUID DETECTORS FOR DETECTION OF ALPHA, NEUTRON, AND OTHER SIGNATURES OF SPECIAL NUCLEAR MATERIALS IN NUCLEAR WASTE REPROCESSING FACILITIES
… Typically the CTMFD is used to detect external neutron sources and internal alpha emitting sources. This work expanded those detection options to include internal fission events, both spontaneous and externally induced. The CTMFD has been previously shown to have effective discrimination of …
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Selective Deuteron Acceleration using Target Normal Sheath Acceleration
… versatility of an ion beam for the generation of neutrons can be improved by tailoring which ions are accelerated. Nominally, the dominant species accelerated is the lightest present on a target surface typically contaminated with hydrocarbons and water: protons. This work elucidates a method of …
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Industrial applications of photonuclear resonance excitation
… feasibility of using bremsstrahlung irradiation sources to produce isomers for industrial applications. In contrast with charged particle based isomer production, the use of high energy photons allows for the irradiation and production of isomers in bulk materials. The commercial availability of …
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