Tesis sobre el tema "Radiography neutron"
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Klein, Dennis William. "Low fluence neutron radiography techniques". Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42613.
Texto completoDawson, Martin Nicholas. "Applications of neutron radiography & tomography". Thesis, University of Leeds, 2008. http://etheses.whiterose.ac.uk/1641/.
Texto completoAbdelrahman, Magdy Shehata. "Scattering correction and image restoration in neutron radiography and computed tomography". Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3025066.
Texto completoChen, Kun. "A study of spectroscopic, cold neutron radiography". [Bloomington, Ind.] : Indiana University, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3240030.
Texto completo"Title from dissertation home page (viewed July 16, 2007)." Source: Dissertation Abstracts International, Volume: 67-10, Section: B, page: 5819. Adviser: Hans-Otto Meyer.
Jo, Young Gyun. "Development of a thermal neutron imaging facility for real time neutron radiography and computed tomography /". Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Texto completoFink, David Walter. "Detecting corrosion in aircraft components using neutron radiography". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/39993.
Texto completoBorges, Nicholas P. "Improving Imaging Techniques and Resolution in Neutron Radiography". Digital WPI, 2020. https://digitalcommons.wpi.edu/etd-dissertations/604.
Texto completoANDRADE, MARCOS L. G. "Radiografia com elétrons induzida por nêutrons: Neutron induced eletron radiography". reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11610.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
Woodward, Stephanie. "Development and applications of a pulsed neutron radiography system". Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/46916.
Texto completoMatsubayashi, Masahito. "Study on development of advanced neutron radiography imaging techniques". Kyoto University, 2005. http://hdl.handle.net/2433/144678.
Texto completo0048
新制・課程博士
博士(エネルギー科学)
甲第11690号
エネ博第106号
新制||エネ||17(附属図書館)
23333
UT51-2005-D439
京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻
(主査)教授 三島 嘉一郎, 教授 代谷 誠治, 教授 川端 祐司
学位規則第4条第1項該当
Chen, Gongyin 1968. "Fast neutron resonance radiography for element imaging : theory and applications". Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8681.
Texto completoIncludes bibliographical references (p. 140-143).
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 obtained from fast neutron radiographic images taken at different neutron energies chosen to cover the resonance cross section features of one or more elements. A radiographic image provides the 2-D mapping of the sum of elemental contents (weighted by the attenuation coefficients) and transmission measurements taken at different neutron energies form a set of linear equations, which can be solved to map individual elemental contents. Explosives and drugs can be identified by their characteristic elemental composition. The object-detector assembly rotates around the neutron source and different energy (2-6 MeV) neutrons can be obtained at different angles from a DD neutron source. A fixed-energy RFQ (2.3 MeV deuteron energy) with a thick target (0.4-0.8 MeV) can be used to generate fast neutrons. The physics of image formation in fast neutron radiography has been studied and a thick (4 cm) plastic scintillator has been recommended as the neutron detector.
(cont.) Variance-checking median filters have been recommended for removing sparkles in the digital image and the direct Householder Transform has been used to solve the ill-conditioned Least-Squares problem. Source shielding for 2x109 neutrons/second has been suggested. Experiments and simulation have proven NRR to be effective. Explosives can be identified with their high nitrogen and oxygen content and drugs with their high C/O ratio. With a 10 [mu]A deuteron current and 6 atmosphere-cm D2 gas target, total imaging time for each piece is expected to be 1-2 minutes. Because multiple objects can be inspected at the same time, it is possible to meet the FAA standard of 8 seconds per piece. Spatial resolution of the image is estimated to be -7.5 mm.
by Gongyin Chen.
Ph.D.
Puffer, Donald B. "Moderator design for accelerator based neutron radiography and tomography systems". Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/37528.
Texto completoDaniels, Graham Clinton. "Observing flow using fast neutron radiography and positron emission particle tracking". Doctoral thesis, Faculty of Science, 2021. http://hdl.handle.net/11427/33606.
Texto completoZapp, Andrew M. "Design and Development of an External Fast Neutron Beam Facility at the Ohio State University Research Reactor". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1545075104197272.
Texto completoChuirazzi, William C. "Combinatorial Optimization of Scintillator Screens for Digital Neutron Imaging". The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1586903047809812.
Texto completoRaas, Whitney. "Towards the development of an explosives detection system using Neutron Resonance Radiography". Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41290.
Texto completoIncludes bibliographical references (leaves 183-188).
Detection of conventional explosives remains a challenge to air security, as indicated by recent reports detailing lapses in security screening and new requirements that mandate screening 100% of checked luggage. Neutron Resonance Radiography (NRR) has been under investigation as a supplement to conventional x-ray systems as a non-invasive, non-destructive means of detecting explosive material in checked luggage. Using fast (1-6 MeV) neutrons produced by an accelerator-based D(d,n)3He reaction and a scintillator-coupled CCD camera, NRR provides both an imaging capability and the ability to determine the chemical composition of materials in baggage or cargo. Theoretical studies and simulations have shown the potential of NRR. This thesis takes the first step towards experimental implementation using a deuterium target for multiple-element discrimination. A new neutron source has been developed to provide the high-flux neutron beam required for NRR while simultaneously minimizing gamma ray production. The gas target incorporates a 4 atm D2 gas chamber, separated from the accelerator beamline with thin, 5 [tm tungsten or 7 [im molybdenum foils supported by a honeycomb lattice structure to increase structural integrity and provide a heat removal pathway. An argon gas cooling system is incorporated to cool the target and thus increase the neutron flux. The gas target has been shown to withstand 3.0 MeV deuteron beam currents in excess of 35 ýLA for extended periods without failure, resulting in a neutron flux of 6.6 x 107 neutrons/sr/LA/s. A neutron imaging system was designed to detect the fast neutrons and produce a digital image of objects for analysis.
(cont.) Two neutron detectors, Eljen plastic scintillator EJ-200 and a ZnS(Ag) scintillating screen were tested for their suitability to NRR. Although ZnS(Ag) has a lower detection efficiency, its resolution, minimal light dispersion, and insensitivity to gamma rays made it the more favorable material. An Apogee Instruments, Inc., Alta U9 CCD camera was used to record the light from the scintillator to create radiographs. The gas target and neutron detection system were used to evaluate the results of experimental work to determine the feasibility of NRR. These experiments ultimately indicated that although NRR has promise, significant challenges regarding neutron flux and image processing must be overcome before the technique can be implemented as an explosives detection system. Suggestions are made for improvements.
by Whitney Lyke Raas.
Ph.D.
Kardjilov, Nikolay. "Further developments and applications of radiography and tomography with thermal and cold neutrons". [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969348320.
Texto completoGrünauer, Florian. "Design, optimization, and implementation of the new neutron radiography facility at FRM-II". [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=978958950.
Texto completoBickerton, M. L. "Development of improved techniques for the neutron radiography of CF188 flight control surfaces". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0006/MQ44833.pdf.
Texto completoMENEZES, MARIO O. de. "Radiografia com neutrons em tempo - real". reponame:Repositório Institucional do IPEN, 2000. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9284.
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Tese [Doutoramento]
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
MENEZES, MARIO O. de. "Desenvolvimento e aplicacao da tecnica da radiografia de neutrons por conversao direta e indireta". reponame:Repositório Institucional do IPEN, 1994. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10366.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
Barritt, Andrew Stephen. "Detection of hydrogen embrittlement in steel and steel alloys using methods of neutron radiography". Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/32597.
Texto completoClark, Michael A. R. "Application of thermal neutron radiography for the mass transport of moisture through freezing soil". Thesis, Aston University, 1989. http://publications.aston.ac.uk/14320/.
Texto completoTurkoglu, Danyal J. "Design, Construction and Characterization of an External Neutron Beam Facility at The Ohio State University Nuclear Reactor Laboratory". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1325228897.
Texto completoANDRADE, MARCOS L. G. "Caracterizacao de sistemas filme-conversor para radiografia com neutrons". reponame:Repositório Institucional do IPEN, 2002. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10986.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
PEREIRA, MARCO A. S. "Emprego dos policarbonatos makrofol-de e CR-30 em radiografia com neutrons". reponame:Repositório Institucional do IPEN, 2000. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9293.
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Dissertacao (Mestrado)
IPEN/D
Intituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP
VITUCCI, GIUSEPPE. "Advances in instruments and methods for neutron transmission imaging". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2019. http://hdl.handle.net/10281/241081.
Texto completoThe work presented in this thesis focuses on the development and improvement of instrumentation and methods applied to neutron transmission imaging. In particular, the research activities have been performed at the "Imaging and Materials Science and Engineering" (IMAT) instrument. This facility is a part of the ISIS neutron source at the Rutherford Appleton Laboratory, in UK. The neutrons here are produced by spallation of a tungsten target hit by protons with energy of 800 MeV. The resulting neutrons are then moderated and convoyed through beam guides towards the IMAT experimental area. The neutrons spectrum in this case is characterized by the presence of thermal and cold neutrons with a wavelength in the range of 0.68 - 6.8 A. IMAT has been designed to acquire neutron pulses in Time-Of-Flight mode, by recording the time of arrival of neutrons, related to their energy, with a maximum of 10 ns timing resolution. This analysis is performed with a new generation detector, that is a combination of a MicroChannel Plate neutron converter with a TIMEPIX electronic readout. By means of this apparatus, radiographies and tomographies with a field of view of 28 mm^2 can be generated with a spatial resolution of 55 \textmu m and with respect to specific neutron energies. Beside this device, a larger CMOS camera can be used in combination with 6LiF/ZnS based neutron screen scintillators to acquire images up to 200 * 200 mm^2 in white-beam imaging. Such configuration opens several possibilities in different case scenarios. In one hand, the energy-resolved neutron imaging technique can be used to investigate the phase fraction composition and texture of the samples via Bragg Edge analysis software tools, at the cost of a reduced field of view. On the other hand, bigger samples can be studied with standard CMOS or CCD based white-beam imaging cameras, but loosing any information about the energy of the incoming neutrons. In this work, the first part is devoted to the description of the IMAT instrumentation, including the beamline design, the experimental area and the detectors. The second part is directed to case studies that made use of these novel instrumentation and imaging techniques. In particular, the cultural heritage takes advantage of such non-destructive methods where small and delicate specimens must be analysed. In this class of examples, a "soufflè" pearl was considered. The peculiarity of these cultured pearls resides in the fact that they are empty inside. The inspection of the morphological structure of the inner part, as well as the individuation of the different orientations of the nacres crystallites was conducted with energy-resolved imaging. A second experiment, presented in this thesis, regards the diagnosis of a series of metallic grids with a size up to 200 * 10 mm^2. For this case, a fast and non destructive way to verify the thickness of 1 um boron carbide layer deposited over the lamellae was successfully implemented, within an uncertainty of 120 nm. The third part is directed to show two new methods developed to improve the MCP detector camera in terms of spatial resolution and reliability. For what concerns the spatial resolution, a new procedure based on a centroiding algorithm has been tested. This acquisition method enables the possibility to go over the physical constraint given by the dimension of the pixels of the electronic readout and to acquire images with a resolutions up to four times higher. Furthermore, an improvement to the resulting images generated by the MCP detector has been developed, based on a post-processing approach. Actually, one of the weak spots of the TIMEPIX readout installed on the MCP detector is that it is constituted by four matrices of pixels assembled together. This brings to noticeable artifacts which, in some cases, may produce issues in the data analysis. A procedure, including a customized software, was implemented to fix such problem.
Harris, Thomas C. (Thomas Cameron). "High Resolution Quantitative Auto-Radiography to determine microscopic distributions of B-10 in neutron capture therapy". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/41271.
Texto completoIncludes bibliographical references.
The success of Boron Neutron Capture Therapy (BNCT) is heavily dependent on the microscopic distribution of B-10 in tissue. High Resolution Quantitative Auto-Radiography (HRQAR) is a potentially valuable analytical tool due to its ability to simultaneously visualize boron distributions and tissue histology. While powerful, the technique has fallen into disuse, largely due to its complexity. HRQAR was reconstituted, and its accuracy was verified with test samples. Numerous improvements were made to make the process easier and more efficient. Permanent staff members at the Institute were trained in the technique, ensuring the continued vitality of HRQAR. The image acquisition equipment and analysis software were modernized, and made more user-friendly. The microdosimetry analysis software was updated to current versions of programming environments and personal computer operating systems. Verification tests were conducted to ensure the continued accuracy of the underlying algorithms. Several experiments were conducted to demonstrate the applications of HRQAR. One focus of current BNCT research is the development of new boron delivery agents, so a potential new compound was compared with a current-generation boron compound. In order to underscore the broader range of utility of HRQAR, another experiment was conducted using the auto-radiography technique as verification of selective microvasculature irradiation.
by Thomas C. Harris.
S.M.
Yoon, Il. "Two-phase flow dynamics by real-time neutron imaging in oscillating heat pipe". Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5694.
Texto completoThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 19, 2009) Includes bibliographical references.
Watts, Michael Robert. "The analysis of diffraction measurements of internal strains in metal matrix composites". Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313918.
Texto completoCools, Antoine. "Beta and neutron imaging with an optical readout Micromegas detector". Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASP090.
Texto completoGaseous detectors have demonstrated, over the past decades, their high performance for imaging radioactive particles, achieving spatial resolutions below 100 µm. The scintillating properties of certain gas mixtures, combined with the significant gain of gaseous detectors and the use of a low-noise camera, have enabled the use of scintillation light for imaging. This approach allows for a large detection surface and high spatial resolution while achieving real-time imaging at a low cost per pixel, with low data analysis complexity. The main objectives of this thesis are to optimize the spatial resolution and sensitivity of the detector, either by an "event-by-event" acquisition method with short image acquisition times or by "integration" with long acquisition times.An innovative glass Micromegas detector for optical readout has been developed, taking advantage of the inherently high spatial resolution of the Micromegas detector. The adaptability of the Micromegas detector's gain, due to the avalanche amplification mechanism, allows it to cover a wide range of particle fluxes and energies. During this thesis, imaging measurements were performed using sources with radioactivity levels below one Becquerel and energies of a few keV, up to fluxes characteristic of a synchrotron and a spallation source, with energies exceeding one MeV.The light yield of the detector was studied for different gas mixtures and various gain values under X-ray irradiation to optimize the detector's sensitivity. The homogeneity and precision of the detector's response were characterized by X-ray radiography. The Point Spread Function (PSF) of the optical readout Micromegas was measured using a parallel X-ray beam a few microns thick, generated by synchrotron radiation. This measurement allowed us to determine the detector's spatial resolution for different configurations and to identify and quantify the effects involved. The impact of the micro-mesh and pillars on the detector's scintillation response was also observed and quantified.Two applications were chosen to illustrate the potential of the optical readout Micromegas: autoradiography, for the quantification of very low-activity tritiated samples and high-resolution neutron radiography in highly radioactive environments.Autoradiography and radioactive counting of low-energy beta radiation were performed with tritiated glucose samples. Activities below one Becquerel were measured accurately and simultaneously on a large number of samples, while ensuring precise reconstruction of their position. This work validates the possibility of quantifying the concentration of anticancer drugs at the scale of single tumor cells.Finally, the use of the optical readout Micromegas for neutron imaging was demonstrated using a spallation source which produces thermal neutrons with a flux of approximately 10⁸ n. s⁻¹cm⁻ ² mA⁻¹. The uniformity of the detector's response was studied, and the effects of the diffusion and the mean free path of particles in the gas on image sharpness were measured and compared to a simulation. A spatial resolution on the order of 400 µm was achieved using double-stage amplification within the Micromegas detector
Owejan, Jon. "Neutron radiography study of water transport in an operating fuel cell : effects of diffusion media and cathode channel properties /". Online version of thesis, 2003. http://hdl.handle.net/1850/5279.
Texto completoShawger, Richard Elwood. "Comparative Analysis of PVT Scintillators for the Development of a Fast Neutron Imager". The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1460195672.
Texto completoPEREIRA, MARCO A. S. "Radiografia com partículas alfa induzida por nêutrons". reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11619.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
Zarebanadkouki, Mohsen [Verfasser], Andrea [Akademischer Betreuer] Carminati, Christoph [Akademischer Betreuer] Leuschner y Hans-Jörg [Akademischer Betreuer] Vogel. "Quantitative imaging of water flow in soil and roots using neutron radiography and deuterated water / Mohsen Zarebanadkouki. Gutachter: Christoph Leuschner ; Hans-Jörg Vogel. Betreuer: Andrea Carminati". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://d-nb.info/1044770031/34.
Texto completoTraore, Issiaka. "Etude et caractérisation des fonctions de réponse des détecteurs solides de traces nucléaires : applications à la dosimétrie radon et neutron". Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01067060.
Texto completoBreitwieser, Matthias, Riko Moroni, Jonathan Schock, Michael Schulz, Burkhard Schillinger, Franz Pfeiffer, Roland Zengerle y Simon Thiele. "Water management in novel direct membrane deposition fuel cells under low humidification". Elsevier, 2016. https://publish.fid-move.qucosa.de/id/qucosa%3A72518.
Texto completoLieboldt, Matthias y Viktor Mechtcherine. "Einfluss von Rissen auf den Feuchtetransport in textilbewehrtem Beton". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-77943.
Texto completoIn this study water absorption and water permeability were tested on uniaxially preloaded, cracked specimens made of textile reinforced concrete (TRC) and cracked composite specimens (ordinary concrete + TRC) preloaded in bending. The influence of imposed strain on the permeation of water was observed in-situ by using uniaxial tensile tests and described by an analytical model. The transport values for the cracked material correlated with the cracks’ characteristics (number of cracks, crack width). Furthermore, the effect of self-healing phenomena on the transport properties of TRC was considered. The distribution of water in cracked ordinary concrete and cracked composite specimens was studied by means of neutron radiography which provided with a high spatial and temporal resolution. The penetration of water is presented qualitatively and discussed
Rahon, Jill Marie. "Spectroscopic radiography with monoenergetic neutrons for homeland security applications". Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/106688.
Texto completoThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 68-71).
In this thesis, I discuss the hypothesis, testing, and applications of a radiographic 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 differences in the energy dependence of neutron interaction cross sections between hydrogenous materials and those of higher atomic number. These dependencies result in characteristic spectral details of hydrogenous materials which may be analyzed to classify type and areal density of cargo contents. The studies presented here demonstrate that this technique is feasible and suited to the application of national security port monitoring at industry-requisite speeds and cargo dimensions.
by Jill Marie Rahon.
S.M.
Souza, Erica Silvani. "Caracterização de um sistema digital de aquisição de imagens radiográficas utilizando nêutrons térmicos e raios gama para a inspeção de componentes mecânicos". Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=7458.
Texto completoNon-destructive testing is an essential approach whenever a piece of equipment, device, or component should not be submitted to a destructive or invasive procedure due to safety reasons, high costs or other physical or logistics constraints. Within this frame, transmission radiography with gamma-rays and thermal neutrons are unique techniques to inspect an object and unveil its inner structure thanks to their capability to pass through a wide range of materials employed in the manufacturing industry. Roughly, as a rule of thumb, gamma-rays are more attenuated by heavy materials, while thermal neutrons are attenuated by the light ones, making them complementary tools. This work presents the results obtained in the inspection of several mechanical components through neutron and gamma-ray transmission radiography. The 4.46 x 105 n.cm-2.s-1 thermal neutron flux available at the main port of the Argonauta research reactor in Instituto de Engenharia Nuclear has been used as source for the neutron radiographic imaging. The 412 keV gamma-ray emitted by 198Au, also produced in that reactor, has been used as interrogation agent for the gamma radiography. Imaging Plates - IP specifically designed to operate with thermal neutrons or with X-rays have been employed as detectors and storage devices for each of these radiations. These devices exhibit several advantages with regard to the conventional radiographic film. Indeed, besides a higher sensitivity and reusability, a dark chamber and a cumbersome chemical processing is not required for the development. Instead, it is carried out by a laser beam which interrogates the electric state of the crystal lattices of the IP, yielding a final digital image. Performances of both Image Acquisition Systems so constituted have been evaluated with regard to sensitivity, spatial resolution, linearity and dynamic range, including a comparison with the neutron radiographic system employing films and a Gd foil as neutron-to-charged particle converter. Besides this characterization, several pieces of equipment, have been radiographed with both systems aiming at the evaluation of their capability to unveil the inner features of these components and to detect abnormal structures or states. Within this frame, a neutron radiography detected the presence of remaining ceramic material - employed as a mold during the manufacturing process - in the cooling channels of a turbo-fan stator blade, which should be free of it. Neutron and gamma-ray radiographs have also shown the damaged rheostat of an automotive pressure probe, but the last one exhibited a better spatial resolution corroborating thus the results obtained during the characterization of both systems. The homogeneity of distribution of the stuff encapsulated in an explosive lead-gasket used in the aero-space industry has also been verified by neutron radiography, for this metal is fairly transparent to neutrons but opaque enough to the hydrogen-bearing explosive material. A diversity of other instruments and components such as variometer, altimeter, aeronautical compass, automotive fuel injector, photo-camera, computer hard disk, step-motor, electronic connectors and bullets have been as well radiographed with both systems addressing their ability to unveil different features according to the type of the employed interrogating agente.
Allen, M. "Ion Acceleration from the Interaction of Ultra-Intense Lasers with Solid Foils". Washington, D.C : Oak Ridge, Tenn. : United States. Dept. of Energy ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/15011790-SSm9hY/native/.
Texto completoPublished through the Information Bridge: DOE Scientific and Technical Information. "UCRL-TH-208645" Allen, M. 11/24/2004. Report is also available in paper and microfiche from NTIS.
Laurent-Pettersson, Maria. "Etude de complexes du bore en vue d'une application thérapeutique : utilisation de traceurs isotopiques stables du bore et de l'azote, détectés par « radiographie par capture de neutrons »". Rouen, 1992. http://www.theses.fr/1992ROUES005.
Texto completoOuznadji-Ramdane, Houria. "Etude de la distribution du lithium chez la souris, dans l'embryon, dans le cerveau des jeunes et le cerveau des mères, par la radiographie par capture de neutrons". Amiens, 1997. http://www.theses.fr/1997AMIE0119.
Texto completoSingh, Shifali. "Radioscopie X pour les interactions corium-sodium lors d'un scénario d'accident grave". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS114.
Texto completoIn Sodium-cooled Fast Reactors (SFR), hypothetical failure of the core cooling system or the plant protection system may lead to a severe accident scenario. In such a scenario, core materials (fuel and cladding) melt down generating a hot molten mixture called corium. This corium may interact with the coolant (liquid sodium) leading to Fuel Coolant Interaction (FCI) which can generate energetic events and hence jeopardize the reactor structures. The yield of these energetic events strongly depends on the state of the corium-sodium mixture prior to the energetic event. Therefore, the knowledge of the features of the mixture composed of three-phases (i.e., corium, liquid sodium, and sodium vapor) is crucial. The lack of knowledge on the phenomenology of the interaction emphasizes the need to study it with the help of experiments. PLINIUS-2, the future large-mass experimental platform of CEA Cadarache, will be dedicated to experiments aiming at understanding the interaction phenomenology of prototypic corium with coolant (sodium and water). The present research aims to develop a high-energy X-Ray imaging system for this facility, to visualize and better understand the corium-sodium interaction. An image-processing algorithm to analyze the three-phase repartition is also developed to contribute to the improvement of numerical modeling. This Ph.D. research has been executed in three steps. In the first step, a bibliographic study of the past experiments was carried out to better understand the physics of the interaction and the mechanism of fragmentation during corium-sodium interaction. This bibliographic study, along with a statistical analysis of the particle size distribution data of various experiments conducted in the past, revealed that the particles formed in these tests are extremely fine fragments with characteristic diameters smaller than 1 mm. Due to the small particle size and the detection limitations of corium fragments in sodium with our X-Ray system, clouds of particles were detected instead of individual particles. In the second phase, the simulation of clouds of corium particles followed by the designing of phantoms (3D mock-ups) representing the 3-phase medium was carried out. Simulations of clouds of corium fragments in liquid sodium and vapor were performed using the CEA Cadarache in-house tool MODHERATO. Based on the results obtained from the simulations, certain phantoms were designed to conduct some physical experiments. These phantoms representative of the FCI interaction zone were manufactured to experimentally evaluate the performance of the radioscopy system and to facilitate the development and calibration of the image processing software. The third step of this work was dedicated to performing experiments with the phantoms and analyzing the radiographic images by developing an image processing algorithm. Experiments were carried out with phantoms in several configurations with the X-Ray radiography system at the CEA Cadarache KROTOS facility. The radioscopic images obtained were treated by developing a new comprehensive image processing and analysis code called PICSEL to identify the three phases composing the medium. Further verification and validation of the PICSEL software were carried out on a test conducted between corium and water at the KROTOS facility under the Euro-Chinese project “ALISA”. Thus, in this Ph.D. research, an X-Ray imaging system was qualified to visualize the corium-sodium interaction in the future PLINIUS-2-FR facility. A qualitative analysis of the images produced by this system was also performed using the PICSEL software to better characterize the evolution of the three-phase mixture and understand the FCI phenomenon, knowledge of which is deemed essential to improve the safety and designs of future sodium-cooled fast reactors
Guzek, Jacek. "Elemental radiography using fast neutron beams". Thesis, 2012. http://hdl.handle.net/10539/11454.
Texto completoRamushu, Mokgobi Andrew. "High density shielding concrete for neutron radiography". Thesis, 2015. http://hdl.handle.net/10539/17537.
Texto completoLuo, Xin. "Study on Infrastructure Materials Using Neutron Radiography and Diffraction". 2007. http://trace.tennessee.edu/utk_graddiss/234.
Texto completoGilbert, Andrew James 1983. "Measuring fluid phase change in capillary tubes using neutron radiography". Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-05-1491.
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Haas, Derek Anderson 1981. "Development of a neutron radiography and computed tomography system at a university research reactor". Thesis, 2006. http://hdl.handle.net/2152/30078.
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Huang, Chun-Kai y 黃俊愷. "The Measurement of 2D-Neutron Distribution for Tsing Hua Open-pool Reactor Boron Neutron Capture Therapy Beam Using Indirect Neutron Radiography Method". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/68762658339187971170.
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