Download or read book Study of a Directional Detector for Fast Neutrons written by Gerard M. Lebreton and published by . This book was released on 1960 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directional Detection of Fast Neutrons Using a Time Projection Chamber written by and published by . This book was released on 2009 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spontaneous fission in Special Nuclear Material (SNM) such as plutonium and highly enriched uranium (HEU) results in the emission of neutrons with energies in the MeV range (hereafter 'fast neutrons'). These fast neutrons are largely unaffected by the few centimeters of intervening high-Z material that would suffice for attenuating most emitted gamma rays, while tens of centimeters of hydrogenous materials are required to achieve substantial attenuation of neutron fluxes from SNM. Neutron detectors are therefore an important complement to gamma-ray detectors in SNM search and monitoring applications. The rate at which SNM emits fast neutrons varies from about 2 per kilogram per second for typical HEU to some 60,000 per kilogram per second for metallic weapons grade plutonium. These rates can be compared with typical sea-level (cosmogenic) neutron backgrounds of roughly 5 per second per square meter per steradian in the relevant energy range [1]. The fact that the backgrounds are largely isotropic makes directional neutron detection especially attractive for SNM detection. The ability to detect, localize, and ultimately identify fast neutron sources at standoff will ultimately be limited by this background rate. Fast neutrons are particularly well suited to standoff detection and localization of SNM or other fast neutrons sources. Fast neutrons have attenuation lengths of about 60 meters in air, and retain considerable information about their source direction even after one or two scatters. Knowledge of the incoming direction of a fast neutron, from SNM or otherwise, has the potential to significantly improve signal to background in a variety of applications, since the background arriving from any one direction is a small fraction of the total background. Imaging or directional information therefore allows for source detection at a larger standoff distance or with shorter dwell times compared to nondirectional detectors, provided high detection efficiency can be maintained. Directional detection of neutrons has been previously considered for applications such as controlled fusion neutron imaging [2], nuclear fuel safety research [3], imaging of solar neutrons and SNM [4], and in nuclear science [5]. The use of scintillating crystals and fibers has been proposed for directional neutron detection [6]. Recently, a neutron scatter camera has been designed, constructed, and tested for imaging of fast neutrons, characteristic for SNM material fission [7]. The neutron scatter camera relies on the measurement of the proton recoil angle and proton energy by time of flight between two segmented solid-state detectors. A single-measurement result from the neutron scatter camera is a ring containing the possible incident neutron direction. Here we describe the development and commissioning of a directional neutron detection system based on a time projection chamber (TPC) detector. The TPC, which has been widely used in particle and nuclear physics research for several decades, provides a convenient means of measuring the full 3D trajectory, specific ionization (i.e particle type) and energy of charged particles. For this application, we observe recoil protons produced by fast neutron scatters on protons in hydrogen or methane gas. Gas pressures of a few ATM provide reasonable neutron interaction/scattering rates.
Download or read book Directional Fast neutron Detectors written by R. C. Byrd and published by . This book was released on 1992 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CALIBRATION AND TESTING OF A LARGE AREA FAST NEUTRON DIRECTIONAL DETECTOR written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed a new directional fast-neutron detector based on double proton recoil in two separated planes of plastic scintillators with position-sensitive readout. This method allows the energy spectrum of the neutrons to be measured by a combination of peak amplitude in the first plane and time of flight to the second plane. The planes are made up of 1-m long, 10-cm high paddles with photomultipliers at both ends, so that the location of an event along the paddle can be estimated from the time delay between the optical pulses detected at the two ends. The direction of the scattered neutron can be estimated from the locations of two time-correlated events in the two planes, and the energy lost in the first scattering event can be estimated from the pulse amplitude in the first plane. The direction of the incident neutron can then be determined to lie on a cone whose angle is determined by the kinematic equations. The superposition of many such cones generates an image that indicates the presence of a localized source. Setting upper and lower limits on the time of flight allows discrimination between gamma rays, muons and neutrons. Monte Carlo simulations were performed to determine the expected angular resolution and efficiency. These models show that the lower energy limit for useful directional events is about 100 keV, because lower energy neutrons are likely to scatter more than once in the first plane. Placing a shadow bar in front of the detector provides an alternative way to obtain the direction to a point source, which may require fewer events. This method also can provide dual capability as a directional gamma detector.
Download or read book DESIGN OF A LARGE AREA FAST NEUTRON DIRECTIONAL DETECTOR written by P. E. VANIER and published by . This book was released on 2006 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large-area fast-neutron double-scatter directional detector and spectrometer is being constructed using l-meter-long plastic scintillator paddles with photomultiplier tubes at both ends. The scintillators detect fast neutrons by proton recoil and also gamma rays by Compton scattering. The paddles are arranged in two parallel planes so that neutrons can be distinguished from muons and gamma rays by time of flight between the planes. The signal pulses are digitized with a time resolution of one gigasample per second. The location of an event along each paddle can be determined from the relative amplitudes or timing of the signals at the ends. The angle of deflection of a neutron in the first plane can be estimated from the energy deposited by the recoil proton, combined with the scattered neutron time-of-flight energy. Each scattering angle can be back-projected as a cone, and many intersecting cones define the incident neutron direction from a distant point source. Moreover, the total energy of each neutron can be obtained, allowing some regions of a fission source spectrum to be distinguished from background generated by cosmic rays. Monte Carlo calculations will be compared with measurements.
Download or read book Directional Fast Neutron Detection Using a Time Projection Chamber written by and published by . This book was released on 2010 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hazebrouck written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-03 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Application of Semiconductor Radiation Detectors to the Observation of Fast Neutrons written by E. L. Zimmerman and published by . This book was released on 1962 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several methods of utilizing a semiconductor radiation detector for neutron observations have been investigated. Techniques for the application of neutron-sensitive materials to detector surfaces have been developed and the resulting coated detectors have been evaluated as both thermal and threshold detectors. A "good geometry" proton-recoil spectrometer utilizing a semiconductor detector has been built and used to observe fast neutrons. An analytical study of this device resulted in a method which can accurately predict its response as a function of incident neutron energy., hydrogenous radiator thickness, and systm geometry. Good qualitative agreement was observed between the predicted and experimental response
Download or read book NASA Technical Translation written by and published by . This book was released on 1973 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radioactive Elements Advances in Research and Application 2013 Edition written by and published by ScholarlyEditions. This book was released on 2013-06-21 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive Elements—Advances in Research and Application: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Radon. The editors have built Radioactive Elements—Advances in Research and Application: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Radon in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Radioactive Elements—Advances in Research and Application: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1971 with total page 1330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directional Neutron Detectors for Use with 14 MeV Neutrons written by Duane A. Sunnarborg and published by . This book was released on 2005 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current Joint Test Assembly (JTA) neutron monitors rely on knock-on proton type detectors that are susceptible to X-rays and low energy gamma rays. We investigated two novel plastic scintillating fiber directional neutron detector prototypes. One prototype used a fiber selected such that the fiber width was less than 2.1mm which is the range of a proton in plastic. The difference in the distribution of recoil proton energy deposited in the fiber was used to determine the incident neutron direction. The second prototype measured both the recoil proton energy and direction. The neutron direction was determined from the kinematics of single neutron-proton scatters. This report describes the development and performance of these detectors.
Download or read book Handbook of Radioactivity Analysis written by Michael F. L'Annunziata and published by Academic Press. This book was released on 2003-08-27 with total page 1338 pages. Available in PDF, EPUB and Kindle. Book excerpt: & Bull; Describes much practical information for radioactivity monitoring, spectrometric analysis, and radiation dosimetry & bull; Covers state-of-the-art high sample throughput microplate analysis techniques and multi-detector scintillation proximity analysis & bull; Presents the latest methods of rapid electronic radionuclide imaging & bull; Written by twenty-five experts from eight countries & bull; Over 2,000 cited works from the journal referencesP Why This Title? This updated and much expanded Second Edition is a proven authoritative handbook providing the reader with the principles, practical techniques, and procedures for the accurate measurement of radioactivity from the very low levels encountered in the environment to higher levels measured in radioisotope research, clinical laboratories, biological sciences, radionuclide standardization, nuclear medicine, nuclear power, fuel cycle facilities, and the implementation of nuclear safeguards.-
Download or read book Masters Theses in the Pure and Applied Sciences Accepted by Colleges and Universities of the United States written by and published by . This book was released on 1961 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Fast Neutron Generators Volume II written by Julius Csikai and published by CRC Press. This book was released on 1987-09-30 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook reviews those problems and methods of science and technology where the neutrons produced in the 3H/d, N/4He, and 2H/d, n/3He reactions play the main role. This two-volume set: Discusses possible applications of these small generators as thermal neutron sources Enables suitable topics to be selected for education and training, provides a wide range of experiments with the detection of neutrons and charged particles, including the study of shielding and the generator technology itself Gives a review of important operational characteristics of neutron generators and the necessary instruments connected with these applications Provides an account of recent results of fast neutron activation analysis in various fields.
