Download or read book Thermal Neutron Imaging Using A New Pad Based Position Sensitive Neutron Detector written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal neutrons (with mean energy of 25 meV) have a scattering mean free path of about 20 m in air. Therefore it is feasible to find localized thermal neutron sources up to ~30 m standoff distance using thermal neutron imaging. Coded aperture thermal neutron imaging was developed in our laboratory in the nineties, using He-3 filled wire chambers. Recently a new generation of coded-aperture neutron imagers has been developed. In the new design the ionization chamber has anode and cathode planes, where the anode is composed of an array of individual pads. The charge is collected on each of the individual 5x5 mm2 anode pads, (48x48 in total, corresponding to 24x24 cm2 sensitive area) and read out by application specific integrated circuits (ASICs). The high sensitivity of the ASICs allows unity gain operation mode. The new design has several advantages for field deployable imaging applications, compared to the previous generation of wire-grid based neutron detectors. Among these are the rugged design, lighter weight and use of non-flammable stopping gas. For standoff localization of thermalized neutron sources a low resolution (11x11 pixel) coded aperture mask has been fabricated. Using the new larger area detector and the coarse resolution mask we performed several standoff experiments using moderated californium and plutonium sources at Idaho National Laboratory. In this paper we will report on the development and performance of the new pad-based neutron camera, and present long range coded-aperture images of various thermalized neutron sources.
Download or read book A New Pad Based Neutron Detector for Stereo Coded Aperture Thermal Neutron Imaging written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Response of a New Pad based Neutron Detector Developed for Coded Aperture Thermal Neutron Imaging written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Position sensitive Detection of Thermal Neutrons written by Pierre Convert and published by . This book was released on 1983 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Phase I Final Report written by and published by . This book was released on 2001 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: A position sensitive neutron detector was designed and fabricated with bundles of individual detector elements with diameters of 120 mm. These neutron scintillating fibers were coupled with optoelectronic arrays to produce a ''Fiber Detector.'' A fiber position sensitive detector was completed and tested with scattered and thermal neutrons. Deployment of improved 2D PSDs with high signal to noise ratios at lower costs per area was the overall objective of the project.
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 Thermal Neutron Detectors with Discrete Anode Pad Readout written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new two-dimensional thermal neutron detector concept that is capable of very high rates is being developed. It is based on neutron conversion in 3He in an ionization chamber (unity gas gain) that uses only a cathode and anode plane; there is no additional electrode such as a Frisch grid. The cathode is simply the entrance window, and the anode plane is composed of discrete pads, each with their own readout electronics implemented via application specific integrated circuits. The aim is to provide a new generation of detectors with key characteristics that are superior to existing techniques, such as higher count rate capability, better stability, lower sensitivity to background radiation, and more flexible geometries. Such capabilities will improve the performance of neutron scattering instruments at major neutron user facilities. In this paper, we report on progress with the development of a prototype device that has 48 x 48 anode pads and a sensitive area of 24cm x 24cm.
Download or read book Thermal Neutron Spectroscopy Using Position sensitive Detectors Together with Fourier Correlation Time of flight and Single Crystal Techniques written by Jørgen Kjems and published by . This book was released on 1970 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applications of Position Sensitive Detectors to Thermal Neutron Scattering written by Institut Laue-Langevin and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A New Position sensitive Detector for Thermal and Epithermal Neutrons written by Alan Paul Jeavons and published by . This book was released on 1977 with total page 24 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 Two dimensional Position sensitive Detector for Thermal Neutrons written by and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NBS Work on Neutron Resonance Radiography written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: NBS has been engaged in a wide-ranging program in Neutron Resonance Radiography utilizing both one- and two-dimensional position-sensitive neutron detectors. The ability to perform a position-sensitive assay of up to 16 isotopes in a complex matrix has been demonstrated for a wide variety of sample types, including those with high gamma activity. A major part of the program has been the development and application of the microchannel-plate-based position-sensitive neutron detector. This detector system has high resolution and sensitivity, together with adequate speed of response to be used with neutron time-of-flight techniques. This system has demonstrated the ability to simultaneously image three isotopes in a sample with no interference.
Download or read book Response Simulation of a Position sensitive Neutron Detector Using a Computer Program written by Boonchai Boonyapat and published by . This book was released on 1983 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Imaging with Thermal Neutrons written by and published by . This book was released on 1996 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments have been conducted using a modern high-resolution 3He two-dimensional position-sensitive detection chamber combined with coded apertures to produce images by means of thermal neutrons. These images are comparable to those produced by gamma ray imaging, but with some important differences. The detector is much less sensitive to the fast neutrons than to the thermalized component. Therefore, assuming that the neutron source has a fission spectrum, the brightest regions in an image represent moderating material in close proximity to the source, rather than the source itself. Earlier experiments have shown that useful contrast can be produced with thermal neutrons using thin masks made of metallic Cd sheet, but the resolution in those experiments was detector-limited at a few centimeters per pixel. The newer detector can resolve a line image with a fwhm resolution of about 1 mm. The technique could in principle be used in re-entry vehicle on-site inspections to count multiple nuclear warheads. Thermal neutrons carry no detailed spectral information, so their detection should not be as intrusive as gamma ray imaging. This technique can be used in nuclear materials management and arms control.
