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.
Results
Showing 1 to 20 of 22 for “"neutron radiography"”.
-
Applications of neutron radiography & tomography
… represents the investigation and development of neutron imaging techniques as a versatile method that can be used to reveal the presence, position, size, morphology, and chemical composition of structures and materials within a sample. The underlying physics of neutron radiography and tomography …
-
Low fluence neutron radiography techniques
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1997.
-
Beam characterization at the neutron radiography reactor
The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam …
-
Detecting corrosion in aircraft components using neutron radiography
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1996.
-
Neutron radiography with the VPI & SU research reactor
… study to determine the feasibility of neutron radiography with the VPI & SU Research Reactor has been completed. Various experimental facilities of the reactor were tested to determine which gave the best beam parameters. The beam parameters considered were: 1) thermal neutron flux; 2) …
-
Moderator design for accelerator based neutron radiography and tomography systems
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1994.
-
Observing flow using fast neutron radiography and positron emission particle tracking
… flow of material has been studied using fast neutron radiography (FNR) and positron emission particle tracking (PEPT). A new fast neutron imaging system was commissioned at The South African Nuclear Energy Corporation, Pretoria, as part of this study, although FNR measurements were ultimately …
-
Detection of hydrogen embrittlement in steel and steel alloys using methods of neutron radiography
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1994.
-
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 …
-
Interfacial Transport Phenomena of the Non-Wetting Phase in Porous Media: Applied to Polymer Electrolyte Fuel Cell Gas Diffusion Media
… physical assumptions. </p> <p>High resolution neutron radiography is used to measure the liquid content profile across the diffusion media, and the results are compared with the model predictions. When the instrumental broadening attributed to the limited resolution of the measurement is …
-
Spectroscopic radiography with monoenergetic neutrons for homeland security applications
… system which uses the spectral analysis of fast neutrons generated in the 11B(d,n[gamma])12C reaction. Neutron radiography in current use systems employs a total count analysis to reconstruct hydrogenous content in scanned cargoes. This research presents a technique which leverages the large …
-
Intense pulsed neutron generation based on the principle of Plasma Immersion Ion Implantation (PI3) technique
… tritium-deuterium (D-D/ D-T) pulsed neutron generator based on the principle of the Plasma Immersion Ion Implantation (PI3) technique is presented, in terms of investigating development of a compact system to generate an ultra short burst of mono-energetic neutrons (of order 1010 per …
-
Neutron radiographic methods
… the reactor at V.P.I. to provide a satisfactory neutron supply for neutron radiography. Several different specimens including low Z materials and heavier materials such as iron have been used as test objects. The effects of alternate methods of obtaining the radiographs and of the different …
-
Fast neutron resonance radiography for element imaging : theory and applications
Fast Neutron Resonance Radiography (NRR) has been devised as an elemental imaging method, with immediate applications to detecting explosives and drugs in passenger suitcases. In the NRR method, the 2-D elemental mapping of hydrogen, carbon, nitrogen, oxygen and the sum of other elements are …
-
A novel non-invasive optical method for quantitative visualization of pH and oxygen dynamics in soils
… fluorescence imaging set-up and coupled it with neutron radiography to study simultaneously root growth, oxygen depletion by respiration activity and root water uptake. The combined set up was subsequently applied to a structured soil system to map the patchy structure of oxic and anoxic zones …
-
Characterization of the MIT Graphite Exponential Pile
… should be well known. In this thesis neutron radiography was performed on 10 different fuel slugs from the pile to directly measure the thickness of the aluminum cladding and confirm the suspected method of slug fabrication. This sample of fuel slugs had an average clad thickness of …
-
Biomass reforming processes in hydrothermal media
… been unknown. Therefore, the technique of neutron radiography is introduced to the supercritical-water processing field in order to characterize the behavior within these RFVs. This allows for non-invasive, in situ, real-time measurements of precipitation phenomena within thick-walled …
-
Development of a switchable radioisotope generator
… reactions to produce a combination of photons, neutrons, and protons with varying fluxes dependent on target materials and source geometry. The activity/strength of the secondary radiation is further controlled by manipulating the number of alpha particles that can interact with the target …
-
Durability of Cementitious Materials in Arctic Regions: Investigating Freeze-Thaw Damage and Chloride Ingress Diffusion Mechanisms
… in cold and F-T environments. Finally, in situ neutron radiography was utilized for the first time in the literature to track real-time pore water movement in concrete macropores under subzero conditions. The results demonstrated that unfrozen water moved away from the freezing front, which is …
Page 1 of 2