Download or read book High Spatial resolution Fast Neutron Detectors for Imaging and Spectrometry written by Ilan Mor and published by . This book was released on 2013 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploring Fast Neutron Computed Tomography for Non destructive Evaluation of Additive Manufactured Parts written by Ibrahim Oksuz and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron imaging is one of the most powerful non-invasive investigation modalities that finds many applications in various fields such as nuclear industry, homeland security, battery research, and archeology. It provides information about the internal structures of an object as neutrons are absorbed and transmitted at different levels in the object in question. It is complementary to X-ray imaging due to the different interaction mechanisms of X-ray and neutrons with materials. Neutron imaging applications can employ neutrons with different energies. Fast (MeV) neutrons have some advantages such as causing less radioactive transmutation in samples and providing deeper penetration which allows for exploring thicker and denser samples. It also provides good contrast images of objects made of a mix of hydrogenous and metallic elements. With the advent of the CCD technology, new opportunities have become available to perform neutron radiography, which provides 2D images of objects, and tomography, which yields information about objects in 3D, more efficiently. Digital neutron radiography allows the collection and storage the information in a digital environment, which enables a better and quicker data analysis. However, performing neutron imaging requires a well-characterized neutron source and a proper neutron imager, especially if fast neutrons are utilized as their interaction cross sections with materials are relatively smaller. This work explores the advancement of the fast neutron radiograph and tomography. The work includes studies comprising characterizing neutron detectors for fast imaging application, characterizing a fast neutron beam facility, performing fast neutron tomography using various imaging phantoms, and investigating spatial resolution in a fast neutron imaging system. In one study, Polyvinyl Toluene (PVT) (C9H10) based plastic scintillators with different dimensions and flours were investigated in terms of their relative light outputs and spatial resolutions. Due to high hydrogen concentration, PVT scintillators would be a suitable candidate since fast neutrons deposit higher energy as they interact mainly via elastic scattering reactions. This study resulted that thicker scintillators yield higher light output due to a higher amount of scintillation materials whereas they performed worse in spatial resolution because of more neutrons and light scattering. Another study was related to characterizing the Ohio State University Research Reactor (OSURR)’ recently built fast neutron beam facility. Models of the beamline and beam stop were created, and Monte-Carlo simulations were performed to determine the neutron energy spectrum, neutron, and gamma-ray flux, and dose rate distributions. Various thermal neutron filters were investigated, and Cadmium ratios that they provide were experimentally determined. Gamma-ray content in the beam was obtained using Optically Stimulated Luminescence (OSL) dosimeters. Another study investigates fast neutron computed tomography (nCT) using custom-made multi-material complex objects. Total nCT data collection time was as low as 2 hours for some objects. Various materials were resolved in 3D reconstructed images of the objects. Low-Z materials comprising the objects were revealed while being shielded behind high-Z materials. The last study in this work is about the investigation of the possible effects on the system's spatial resolution in a fast neutron imaging system. Results showed that the thicker imaging objects deteriorate the spatial resolution due to the neutron scattering. Simulations provided that the neutron interaction kinematics in PVTs would also degrade the spatial resolution.
Download or read book Neutron Detectors for Scattering Applications written by Yacouba Diawara and published by Springer Nature. This book was released on 2023-08-04 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the most common neutron detectors used in neutron scattering facilities and all of those in use at Oak Ridge National Lab. It starts describing the facilities, instruments and the critical detector parameters needed by various instruments. Then the key components of the 3He-based linear position-sensitive detectors as well as on their electronics, which require particular attention to signal processing and noise reduction, are introduced. One chapter is dedicated to the 3He alternatives where scintillators play a critical role. It also covers emerging neutron detection technologies including semiconductors, vacuum-based devices and their associated readouts, which will be required in the future for high rate and high-resolution neutron detectors. The authors explain the logic behind the choice of materials as well as the various constraints that neutron detectors must respect to be useful. Some of these constraints, such as efficiency and gamma-ray sensitivity are common to all neutron counters while others, like timing resolution, dynamic range, and peak counting rate, depend on the applications. The book guides experts, the nuclear science community, and young scholars through the physical processes and the required electronics in a way that is accessible for those not professionally involved in designing detector’s components and electronic circuits.
Download or read book Neutron Imaging written by Dinesh K. Aswal and published by Springer Nature. This book was released on 2022-04-12 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprehensively presents the concepts of neutron physics and imaging including neutron properties, neutron matter interaction, neutron imaging, comparison with X-ray and physics and design of neutron sources. It discusses how neutron imaging has gained importance as a powerful non-destructive technique to understand the internal structures of materials/engineered components in wide range of industries by increasing their applicability and efficiency. The book also covers the topics of neutron optics and detectors, basic principles of neutron radiography and tomography, related standards, safety, metrology and regulations in neutron imaging. The book presents applications of neutron imaging in the areas of aerospace industry, nuclear power and manufacturing industry, materials science and engineering, geomechanics, national security, biological, and medical domain. Given its scope, the book will be highly beneficial for postgraduate students, researchers and industry professionals working in the area of engineering and physics, especially non-destructive testing and non-destructive evaluation through neutron imaging.
Download or read book Literature Search on Neutron Detectors written by Frances L. Sachs and published by . This book was released on 1951 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutron Radiography written by Garbe,U. and published by Materials Research Forum LLC. This book was released on 2020-02-05 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron radiography represents a powerful non-destructive testing technique that is still very much in development. The book reveals the amazing diversity of scientific and industrial applications of this technique, the advancements of the state-of-art neutron facilities, the latest method developments, and the expected future of neutron imaging.
Download or read book Demonstration of Two dimensional Time encoded Imaging of Fast Neutrons written by and published by . This book was released on 2015 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, we present a neutron detector system based on time-encoded imaging, and demonstrate its applicability toward the spatial mapping of special nuclear material. We also demonstrate that two-dimensional fast-neutron imaging with 2° resolution at 2 m stand-off is feasible with only two instrumented detectors.
Download or read book Review of Current Neutron Detection Systems for Emergency Response written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron detectors are utilized in a myriad of applications--from safeguarding special nuclear materials (SNM) to determining lattice spacing in soft materials. The transformational changes taking place in neutron detection and imaging techniques in the last few years are largely being driven by the global shortage of helium-3 (3He). This article reviews the status of neutron sensors used specifically for SNM detection in radiological emergency response. These neutron detectors must be highly efficient, be rugged, have fast electronics to measure neutron multiplicity, and be capable of measuring direction of the neutron sources and possibly image them with high spatial resolution. Neutron detection is an indirect physical process: neutrons react with nuclei in materials to initiate the release of one or more charged particles that produce electric signals that can be processed by the detection system. Therefore, neutron detection requires conversion materials as active elements of the detection system; these materials may include boron-10 (10B), lithium-6 (6Li), and gadollinium-157 (157Gd), to name a few, but the number of materials available for neutron detection is limited. However, in recent years, pulse-shape-discriminating plastic scintillators, scintillators made of helium-4 (4He) under high pressure, pillar and trench semiconductor diodes, and exotic semiconductor neutron detectors made from uranium oxide and other materials have widely expanded the parameter space in neutron detection methodology. In this article we will pay special attention to semiconductor-based neutron sensors. Finally, modern microfabricated nanotubes covered inside with neutron converter materials and with very high aspect ratios for better charge transport will be discussed.
Download or read book Elements of Slow Neutron Scattering written by J. M. Carpenter and published by Cambridge University Press. This book was released on 2015-09-24 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive and up-to-date introduction to the fundamental theory and applications of slow-neutron scattering.
Download or read book Neutron Imaging and Applications written by Ian S. Anderson and published by Springer Science & Business Media. This book was released on 2009-04-21 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron Imaging and Applications offers an introduction to the basics of neutron beam production in addition to the wide scope of techniques that enhance imaging application capabilities. An instructional overview of neutron sources, detectors, optics and spin-filters allows readers to delve more deeply into the discussions of radiography, tomography and prospective applications available in neutron holography techniques. A section devoted to current applications describes imaging single grains in polycrystalline materials, neutron imaging of geological materials and other materials science and engineering areas. Coverage of thermal neutron imaging of biological tissues, plant physiology, Homeland Security and contraband detection explore the future prospects of this cutting-edge research. Written by key experts in the field, researchers and engineers involved with imaging technologies will find Neutron Imaging and Applications a valuable reference.
Download or read book Characterization of a Neutron Imaging Platform Utilizing a Compact Electronic Neutron Generator for Evaluation of Analog and Digital Neutron Imaging Methods and Techniques written by Michael James Taylor and published by . This book was released on 2019 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unlike X-Rays that interact strongly with the electron cloud surrounding atoms, neutrons interact very weakly with these electrons, but quite strongly with the nucleus of the atom. X-Rays follow a nearly linear trend of decreasing transmission as the atomic number of the element increases. Neutrons follow no such behavior and certain isotopes of elements such as lithium, boron, cadmium, and gadolinium interact very strongly with neutrons, unlike dense elements such as lead or tungsten. This gives neutrons a unique probing capability where X-Rays do not suffice. Neutron imaging is widely used in the commercial sector for munitions and critical aerospace component inspection as well as in the research realm for biological forensics, cultural heritage providence studies, and capturing repetitive processes such as cyclical fluid motion in rotating motors. Current neutron sources are typically nuclear reactors and spallation sources that provide incredibly high neutron yields and flux for the images, leading to reduced image times and/or high spatial resolution as well as new imaging techniques such as computed tomography, polarized neutron imaging, and phase contrast imaging. However, such sources are very expensive, require thorough regulatory oversight, and pose biological hazards from spent nuclear materials. Smaller sources such as sealed tube deuterium-deuterium or deuterium-tritium sources can allow for in-field inspection at a fraction of the cost of a reactor, but don't necessarily provide fast image acquisitions or adequate image quality. This thesis explores a system that is intended to fill the space between weak portable devices and strong, costly, immobile ones. An accelerator-based neutron generator has been designed and manufactured by Phoenix LLC in Madison, WI. This system operates on the principle of deuterium-deuterium fusion, which releases a free 2.45MeV (nominal) neutron in the fusion process. The system can be installed and commissioned in different locations throughout its lifetime and provides for in-field or commercial inspection of components. It has a neutron yield several orders of magnitude higher than sealed-tube neutron sources. The goal herein was to: enhance the performance of the neutron generator through careful beamline design from the source to the target to obtain the maximum neutron yield, optimize the geometry of the neutron moderator and collimator to maximize the imaging metrics of a thermalized and collimated neutron beam free of background gamma and fast neutron radiation contamination, and find efficient neutron detector solutions that can capture high-quality neutron images. Monte Carlo simulations were extensively employed for these optimization efforts. The system has been shown to produce high quality neutron radiographs in terms of contrast, noise, and resolution, using many different techniques for imaging. Many materials were explored for moderation and shielding, and many neutron detectors were researched and experimented with to demonstrate advantages and disadvantages for their use on the Phoenix neutron imaging system. Sample images will be shown and discussed including conventional radiography using medical, industrial, and photographic film, 2-dimension digital imaging using pixelated cameras such as Charge Coupled Devices (CCD), Complementary Metal Oxide Semiconductors (CMOS), amorphous Silicon (aSi), and Computed Radiography (CR). Neutron Computed Tomography (nCT) is demonstrated as a 3-dimensional imaging technique as well. Case studies will be discussed and options for further optimization for collimator, moderator, and detector designs will be outlined. Recommendations for future research will be discussed in the final chapter.
Download or read book Spatial Resolution of Neutron position Scintillation Detectors written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An Intense Pulsed Neutron Source (IPNS) was recently built at Argonne. From the point of view of neutron detection a pulsed source has two characteristics which are basically different from those of a steady-state source such as a reactor: broad spectrum of neutron energies in which a greater fraction of the flux is in the epithermal range, and high instantaneous neutron flux. A detector to be used with a pulsed source should therefore have: high neutron detection efficiency extending to epithermal energies, and high instantaneous count-rate capability. In response to these requirements a new neutron position-sensitive detector was developed. The detector is comprised of an array of photomultiplier tubes coupled to a thin 6Li-glass scintillator. The principle of operation is similar to that of the Anger gamma-ray camera used in nuclear medicine.
Download or read book Remote Compositional Analysis written by Janice L. Bishop and published by Cambridge University Press. This book was released on 2019-11-28 with total page 655 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive overview of the spectroscopic, mineralogical, and geochemical techniques used in planetary remote sensing.
Download or read book Modern essays written by and published by . This book was released on 1936 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal neutron Detection Based on the Gas Electron Multiplier written by T. L. Van Vuure and published by Delft University Press. This book was released on 2004-01-01 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a Ph.D. dissertation. For probing the structure and dynamics of matter at an atomic, molecular and mesoscopic level, elastic and inelastic neutron scattering, diffractometry, reflectometry and a variety of other neutron scattering methods are of utmost importance. For them the availability of highly efficient and fast large-area position-sensitive neutron detectors is a condition of growing importance. In particular, the upcoming third generation of neutron sources, consisting of high-intensity pulsed spallation neutron sources, in conjunction with current progress in neutron optics will increase the peak neutron flux at the spectrometers' samples positions by more than two orders of magnitude. Consequently, much faster detectors than presently available with improved background are required in order to take full advantage of these increased source strengths and us pulse widths. In addition, due to the higher neutron fluxes, longer flight paths and smaller samples can be used and if higher 'matched' spatial detector resolutions are available better lattice resolutions can be attained. The goal of the research described in this dissertation is to develop a thermal neutron detector that meets as many as possible of the requirements being formulated during the ongoing design of the third generation of neutron sources.
Download or read book The Development of a Fast Neutron Spectrometer Using Silicon Surface Barrier Diodes written by J. J. Baum and published by . This book was released on 1961 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book V ysehorovicko Cernokostelecko a okoli Uhlirskych Janovic written by and published by . This book was released on 1962 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt:
