Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Neutron Multiplicity Easurements With 3he Alternative
Download Neutron Multiplicity Easurements With 3he Alternative full books in PDF, epub, and Kindle. Read online Neutron Multiplicity Easurements With 3he Alternative ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Neutron Multiplicity Measurements with 3He Alternative by :
Download or read book Neutron Multiplicity Measurements with 3He Alternative written by and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Counting neutrons emitted by special nuclear material (SNM) and differentiating them from the background neutrons of various origins is the most effective passive means of detecting SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment are complex due to the presence of high-multiplicity spallation neutrons (commonly known as ''ship effect '') and to the complicated nature of the neutron scattering in that environment. A prototype neutron detector was built using 10B as the converter in a special form factor called ''straws'' that would address the above problems by looking into the details of multiplicity distributions of neutrons originating from a fissioning source. This paper describes the straw neutron multiplicity counter (NMC) and assesses the performance with those of a commercially available fission meter. The prototype straw neutron detector provides a large-area, efficient, lightweight, more granular (than fission meter) neutron-responsive detection surface (to facilitate imaging) to enhance the ease of application of fission meters. Presented here are the results of preliminary investigations, modeling, and engineering considerations leading to the construction of this prototype. This design is capable of multiplicity and Feynman variance measurements. This prototype may lead to a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to fission meters. This paper describes the work performed during a 2-year site-directed research and development (SDRD) project that incorporated straw detectors for neutron multiplicity counting. The NMC is a two-panel detector system. We used 10B (in the form of enriched boron carbide: 10B4C) for neutron detection instead of 3He. In the first year, the project worked with a panel of straw neutron detectors, investigated its characteristics, and developed a data acquisition (DAQ) system to collect neutron multiplicity information from spontaneous fission sources using a single panel consisting of 60 straws equally distributed over three rows in high-density polyethylenemoderator. In the following year, we developed the field-programmable gate array and associated DAQ software. This SDRD effort successfully produced a prototype NMC with*33% detection efficiency compared to a commercial fission meter.
Book Synopsis Neutron Multiplicity, Easurements With 3He Alternative by :
Download or read book Neutron Multiplicity, Easurements With 3He Alternative written by and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Counting neutrons emitted by special nuclear material (SNM) and differentiating them from the background neutrons of various origins is the most effective passive means of detecting SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment are complex due to the presence of high-multiplicity spallation neutrons (commonly known as "ship effect") and to the complicated nature of the neutron scattering in that environment. In this study, a prototype neutron detector was built using 10B as the converter in a special form factor called "straws" that would address the above problems by looking into the details of multiplicity distributions of neutrons originating from a fissioning source. This paper describes the straw neutron multiplicity counter (NMC) and assesses the performance with those of a commercially available fission meter. The prototype straw neutron detector provides a large-area, efficient, lightweight, more granular (than fission meter) neutron-responsive detection surface (to facilitate imaging) to enhance the ease of application of fission meters. Presented here are the results of preliminary investigations, modeling, and engineering considerations leading to the construction of this prototype. This design is capable of multiplicity and Feynman variance measurements. This prototype may lead to a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to fission meters. This paper describes the work performed during a 2-year site-directed research and development (SDRD) project that incorporated straw detectors for neutron multiplicity counting. The NMC is a two-panel detector system. We used 10B (in the form of enriched boron carbide: 10B4C) for neutron detection instead of 3He. In the first year, the project worked with a panel of straw neutron detectors, investigated its characteristics, and developed a data acquisition (DAQ) system to collect neutron multiplicity information from spontaneous fission sources using a single panel consisting of 60 straws equally distributed over three rows in high-density polyethylene moderator. In the following year, we developed the field-programmable gate array and associated DAQ software. Finally, this SDRD effort successfully produced a prototype NMC with ~33% detection efficiency compared to a commercial fission meter.
Book Synopsis Simulations of Neutron Multiplicity Measurements with MCNP-PoliMi by :
Download or read book Simulations of Neutron Multiplicity Measurements with MCNP-PoliMi written by and published by . This book was released on 2010 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The heightened focus on nuclear safeguards and accountability has increased the need to develop and verify simulation tools for modeling these applications. The ability to accurately simulate safeguards techniques, such as neutron multiplicity counting, aids in the design and development of future systems. This work focuses on validating the ability of the Monte Carlo code MCNPX-PoliMi to reproduce measured neutron multiplicity results for a highly multiplicative sample. The benchmark experiment for this validation consists of a 4.5-kg sphere of plutonium metal that was moderated by various thicknesses of polyethylene. The detector system was the nPod, which contains a bank of 15 3He detectors. Simulations of the experiments were compared to the actual measurements and several sources of potential bias in the simulation were evaluated. The analysis included the effects of detector dead time, source-detector distance, density, and adjustments made to the value of [nu]-bar in the data libraries. Based on this analysis it was observed that a 1.14% decrease in the evaluated value of [nu]-bar for 239Pu in the ENDF-VII library substantially improved the accuracy of the simulation.
Book Synopsis Thermal Neutron Multiplicity Measurements Using the Pyrochemical Multiplicity Counter at Lawrence Livermore National Laboratory by :
Download or read book Thermal Neutron Multiplicity Measurements Using the Pyrochemical Multiplicity Counter at Lawrence Livermore National Laboratory written by and published by . This book was released on 1993 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The pyrochemical multiplicity counter designed and built at Los Alamos has been undergoing tests and evaluation at Lawrence Livermore National Laboratory (LLNL). Measurements have been performed using a variety of plutonium oxide and metal materials. The pyrochemical multiplicity counter uses the information contained in the higher moments of the neutron multiplicity distribution to deduce the three unknowns in the assay problem: 24°Pu-effective mass, ([alpha], n) neutron rate, and self-multiplication. This is an improvement over conventional neutron coincidence counting, which must rely on some estimate of the ([alpha], n) neutron rate or self-multiplication to deduce an assay result. Such conventional techniques are generally unsatisfactory for impure materials for which these quantities are unknown. We present the assay results obtained with the pyro-chemical multiplicity counter and discuss the procedures necessary to produce good assay results. Using these procedures, we have obtained assay accuracies of 1%--2% for oxide materials in 1/2 hour measurement times. We also compare these results to those that would have been obtained using conventional neutron assay techniques and discuss the correlations we have observed between assay results and the ratio of total neutron counts in the different rings of the pyrochemical counter.
Book Synopsis Neutron Multiplicity Measurements for Neutron-induced Fission of (sup 233)U and (sup 235)U. by : Raymond L. Reed
Download or read book Neutron Multiplicity Measurements for Neutron-induced Fission of (sup 233)U and (sup 235)U. written by Raymond L. Reed and published by . This book was released on 1973 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An Analysis Technique for Active Neutron Multiplicity Measurements Based on First Principles by :
Download or read book An Analysis Technique for Active Neutron Multiplicity Measurements Based on First Principles written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Passive neutron multiplicity counting is commonly used to quantify the total mass of plutonium in a sample, without prior knowledge of the sample geometry. However, passive neutron counting is less applicable to uranium measurements due to the low spontaneous fission rates of uranium. Active neutron multiplicity measurements are therefore used to determine the 235U mass in a sample. Unfortunately, there are still additional challenges to overcome for uranium measurements, such as the coupling of the active source and the uranium sample. Techniques, such as the coupling method, have been developed to help reduce the dependence of calibration curves for active measurements on uranium samples; although, they still require similar geometry known standards. An advanced active neutron multiplicity measurement method is being developed by Texas A & M University, in collaboration with Los Alamos National Laboratory (LANL) in an attempt to overcome the calibration curve requirements. This method can be used to quantify the 235U mass in a sample containing uranium without using calibration curves. Furthermore, this method is based on existing detectors and nondestructive assay (NDA) systems, such as the LANL Epithermal Neutron Multiplicity Counter (ENMC). This method uses an inexpensive boron carbide liner to shield the uranium sample from thermal and epithermal neutrons while allowing fast neutrons to reach the sample. Due to the relatively low and constant fission and absorption energy dependent cross-sections at high neutron energies for uranium isotopes, fast neutrons can penetrate the sample without significant attenuation. Fast neutron interrogation therefore creates a homogeneous fission rate in the sample, allowing for first principle methods to be used to determine the 235U mass in the sample. This paper discusses the measurement method concept and development, including measurements and simulations performed to date, as well as the potential limitations.
Book Synopsis 3He Alternatives Summary Report by :
Download or read book 3He Alternatives Summary Report written by and published by . This book was released on 2015 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the 3He consumed by neutron-based safeguards assay systems is used in neutron coincidence and neutron multiplicity counting systems. Detection methods for the limited number of total neutron counting applications are not considered in this report, but it is believed that the boron-lined tubes [1, 2] already developed for portal monitoring applications will serve as a suitable replacement for those measurements. In this report, we discuss the potential replacement technologies that are most suitable for use in safeguards applications.
Book Synopsis 14 MeV Neutrons by : Vladivoj Valkovic
Download or read book 14 MeV Neutrons written by Vladivoj Valkovic and published by CRC Press. This book was released on 2015-08-25 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the often difficult and time-consuming effort of performing experiments with fast (14 MeV) neutrons, these neutrons can offer special insight into nucleus and other materials because of the absence of charge. 14 MeV Neutrons: Physics and Applications explores fast neutrons in basic science and applications to problems in medicine, the envir
Book Synopsis Calculations for Fission Neutron and Gamma Multiplicity Measurements by : J. P. Theobald
Download or read book Calculations for Fission Neutron and Gamma Multiplicity Measurements written by J. P. Theobald and published by . This book was released on 1972 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Deployable Dead Time Corrections for Neutron Multiplicity Measurements Accounting for Neutron Correlations and Multiple Detector Chains by :
Download or read book Deployable Dead Time Corrections for Neutron Multiplicity Measurements Accounting for Neutron Correlations and Multiple Detector Chains written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Passive Neutron Multiplicity Measurements of High Mass Plutonium Samples by :
Download or read book Passive Neutron Multiplicity Measurements of High Mass Plutonium Samples written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Simulation of Neutron Multiplicity Measurements Using Geant4 - Open Source Software for Nuclear Arms Control by : Moritz Kütt
Download or read book Simulation of Neutron Multiplicity Measurements Using Geant4 - Open Source Software for Nuclear Arms Control written by Moritz Kütt and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis International Seminars On Nuclear War And Planetary Emergencies - 49th Session by : Zichichi Antonino
Download or read book International Seminars On Nuclear War And Planetary Emergencies - 49th Session written by Zichichi Antonino and published by World Scientific. This book was released on 2019-03-26 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 49th Session of the International Seminars on Nuclear War and Planetary Emergencies held in Erice, Sicily. This Seminar has again gathered, in 2016, over one hundred scientists from 43 countries in an interdisciplinary effort that has been going on for the last 33 years, to examine and analyze planetary problems which had been followed up, all year long, by the World Federation of Scientists' Permanent Monitoring Panels.
Book Synopsis Spatial Multiplication Model as an Alternative to the Point Model in Neutron Multiplicity Counting by :
Download or read book Spatial Multiplication Model as an Alternative to the Point Model in Neutron Multiplicity Counting written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An Alternative Method for Analyzing Active Multiplicity Data by :
Download or read book An Alternative Method for Analyzing Active Multiplicity Data written by and published by . This book was released on 2005 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Neutron Multiplicity Measurements on Pu-Bearing Material with the Euratom Time Correlation Analyser by :
Download or read book Neutron Multiplicity Measurements on Pu-Bearing Material with the Euratom Time Correlation Analyser written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Multiplicity Detector for Neutron Capture Measurements by : Noel J. Drindak
Download or read book A Multiplicity Detector for Neutron Capture Measurements written by Noel J. Drindak and published by . This book was released on 1987 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
