Download or read book Modeling and Analysis of a Portable Solid state Neutron Detection System for Spectroscopic Applications written by Thomas Michael Oakes and published by . This book was released on 2012 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper discusses a new neutron detection system that allows local volumetric identification of fast neutron thermalization in the context of forming a solid state Bonner-like neutron spectrometer. The resulting departure and subsequent improvement from the classical Bonner spectrometer is that the entire moderating volume is sampled locally for thermal neutrons. Such volumetric resolution is possible through the layering of weakly perturbing and pixilated high thermal efficiency solid state neutron detectors into a cylindrically symmetric neutron moderator. The overall system exhibits >10% total detection efficiency over the neutron energy range from thermal to 20 MeV and the data can be acquired simultaneously from all detector elements in a single measurement. These measurements can be used to infer information on incident neutron energy spectra and direction, which provides capabilities not available in current systems. The end result is a highly efficient, man-portable device with significantly improved methods for determination of pervading neutron energy spectra and the corresponding dose equivalent.
Download or read book Cross Correlation Calculations and Neutron Scattering Analysis for Portable Solid State Neutron Detection System written by Andrea Saltos and published by . This book was released on 2015 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: In efforts to perform accurate dosimetry, Oakes et al. [Nucl. Intrum. Mehods. (2013)] introduced a new portable neutron dosimeter for spectroscopy applications. The system utilizes high thermal efficiency Li-6 based detectors to generate measurement signals that are used to infer information of the incident neutron source. The problem associated to deduce dose from the dosimeter response is addressed by applying a cross-correlation method which allows estimation of dose with average errors less than 15%. In this work, an evaluation of the performance of this system was extended to take into account new correlation techniques and neutron scattering contribution. To test the effectiveness of correlations, the Distance correlation, Pearson Product-Moment correlation, and their weighted versions were performed between simulated detector responses obtained from nine different test sources, and the spatial response for known input source spectra. Results indicate that there is no advantage of using the Distance Correlation over the Pearson Correlation, and that weighted versions of these correlations do not increase their performance in evaluating dose. To evaluate the effect produced by room-return neutrons on the dosimeter readings, dosimeter responses were simulated for five isotropic neutron sources placed inside different sizes of rectangular concrete rooms. Results show that the contribution of scattered neutrons to the response of the dosimeter can be significant, so that for most cases the dose is over predicted with errors as large as 500%. A possible method to correct for the contribution of room-return neutrons is also assessed and can be used as a good initial estimate on how to approach the problem.
Download or read book Vibrational Spectroscopy With Neutrons With Applications In Chemistry Biology Materials Science And Catalysis written by Philip C H Mitchell and published by World Scientific. This book was released on 2005-06-15 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inelastic neutron scattering (INS) is a spectroscopic technique in which neutrons are used to probe the dynamics of atoms and molecules in solids and liquids. This book is the first, since the late 1960s, to cover the principles and applications of INS as a vibrational-spectroscopic technique. It provides a hands-on account of the use of INS, concentrating on how neutron vibrational spectroscopy can be employed to obtain chemical information on a range of materials that are of interest to chemists, biologists, materials scientists, surface scientists and catalyst researchers. This is an accessible and comprehensive single-volume primary text and reference source.
Download or read book Development of A Self Biased High Efficiency Solid State Neutron Detector for MPACT Applications written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron detection is an important aspect of materials protection, accounting, and control for transmutation (MPACT). Currently He-3 filled thermal neutron detectors are utilized in many applications; these detectors require high-voltage bias for operation, which complicates the system when multiple detectors are used. In addition, due to recent increase in homeland security activity and the nuclear renaissance, there is a shortage of He-3, and these detectors become more expensive. Instead, cheap solid-state detectors that can be mass produced like any other computer chips will be developed. The new detector does not require a bias for operation, has low gamma sensitivity, and a fast response. The detection system is based on a honeycomb-like silicon device, which is filled with B-10 as the neutron converter; while a silicon p-n diode (i.e., solar cell type device) formed on the thin silicon wall of the honeycomb structure detects the energetic charged particles emitted from the B-10 conversion layer. Such a detector has ~40% calculated thermal neutron detection efficiency with an overall detector thickness of about 200?m. Stacking of these devices allows over 90% thermal neutron detection efficiency. The goal of the proposed research is to develop a high-efficiency, low-noise, self-powered solid-state neutron detector system based on the promising results of the existing research program. A prototype of this solid-state neutron detector system with sufficient detector size (up to 8-inch diam., but still portable and inexpensive) and integrated with interface electronics (e.g., preamplifier) will be designed, fabricated, and tested as a coincidence counter for MPACT applications. All fabrications proposed are based on silicon-compatible processing; thus, an extremely cheap detector system could be massively produced like any other silicon chips. Such detectors will revolutionize current neutron detection systems by providing a solid-state alternative to traditional gas-based neutron detectors.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-11 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976-05 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1981 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1976 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications written by United States. National Bureau of Standards and published by . This book was released on 1981 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transactions of the American Nuclear Society written by and published by . This book was released on 1996 with total page 936 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 1980 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Instrumentation and Methodologies for Determination of Free Neutron Characteristics written by Cory Blake Hoshor and published by . This book was released on 2017 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measuring neutron source‐dependent free neutron properties over a large neutron energy range, with human‐portable instrumentation, continues to push the frontier of neutron detection instrumentation design and analysis techniques. In addition, a variety of nuclear nonproliferation and health physics applications require instrumentation that can provide free neutron property measurement and analysis in real time. To overcome the challenges inherent to these applications and advance the state of the current art in neutron detection instrumentation, the first representatives of a new class of solid-state moderating-type neutron spectrometer have been designed, modeled, fabricated, and tested. This work introduces state-of-the-art human-portable instruments by discussing the fundamental theory of their operation, investigating and analyzing—via Monte Carlo simulation—the principle considerations for optimal instrument design, and empirically evaluating the capability of each of the fabricated spectrometers to meet the application needs. Utilizing the unique three dimensional neutron thermalization information afforded by this new class of instrumentation, novel algorithmic methodologies are introduced to determine free neutron characteristics of interest to the aforementioned applications in real time.
Download or read book Publications of the National Bureau of Standards Catalog written by United States. National Bureau of Standards and published by . This book was released on 1980 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multivariate Optimization of Neutron Detectors Through Modeling written by Martin Rodney Williamson and published by . This book was released on 2010 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the eminent shortage of 3He, there exists a significant need to develop a new (or optimize an existing) neutron detection system which would reduce the dependency on the current 3He-based detectors for Domestic Nuclear Detection Office (DNDO) applications. The purpose of this research is to develop a novel methodology for optimizing candidate neutron detector designs using multivariate statistical analysis of Monte Carlo radiation transport code (MCNPX) models. The developed methodology allows the simultaneous optimization of multiple detector parameters with respect to multiple response parameters which measure the overall performance of a candidate neutron detector. This is achieved by applying three statistical strategies in a sequential manner (namely factorial design experiments, response surface methodology, and constrained multivariate optimization) to results generated from MCNPX calculations. Additionally, for organic scintillators, a methodology incorporating the light yield nonproportionality is developed for inclusion into the simulated pulse height spectra (PHS). A Matlab® program was developed to post-process the MCNPX standard and PTRAC output files to automate the process of generating the PHS thus allowing the inclusion of nonlinear light yield equations (Birks equations) into the simulation of the PHS for organic scintillators. The functionality of the developed methodology is demonstrated on the successful multivariate optimization of three neutron detection systems which utilize varied approaches to satisfying the DNDO criteria for an acceptable alternative neutron detector. The first neutron detection system optimized is a 3He-based radiation portal monitor (RPM) based on a generalized version of a currently deployed system. The second system optimized is a 6Li-loaded polymer composite scintillator in the form of a thin film. The final system optimized is a 10B-based plastic scintillator sandwiched between two standard plastic scintillators. Results from the multivariate optimization analysis include not only the identification of which factors significantly affect detector performance, but also the determination of optimum levels for those factors with simultaneous consideration of multiple detector performance responses. Based on the demonstrated functionality of the developed multivariate optimization methodology, application of the methodology in the development process of new candidate neutron detector designs is warranted.
Download or read book ERDA Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:
