Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Download Deployable Dead Time Corrections For Neutron Multiplicity Measurements Accounting For Neutron Correlations And Multiple Detector Chains full books in PDF, epub, and Kindle. Read online Deployable Dead Time Corrections For Neutron Multiplicity Measurements Accounting For Neutron Correlations And Multiple Detector Chains ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
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:
Download or read book A Physics Investigation of Deadtime Losses in Neutron Counting at Low Rates with Cf252 written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 252Cf spontaneous fission sources are used for the characterization of neutron counters and the determination of calibration parameters; including both neutron coincidence counting (NCC) and neutron multiplicity deadtime (DT) parameters. Even at low event rates, temporally-correlated neutron counting using 252Cf suffers a deadtime effect. Meaning that in contrast to counting a random neutron source (e.g. AmLi to a close approximation), DT losses do not vanish in the low rate limit. This is because neutrons are emitted from spontaneous fission events in time-correlated 'bursts', and are detected over a short period commensurate with their lifetime in the detector (characterized by the system die-away time,?). Thus, even when detected neutron events from different spontaneous fissions are unlikely to overlap in time, neutron events within the detected 'burst' are subject to intrinsic DT losses. Intrinsic DT losses for dilute Pu will be lower since the multiplicity distribution is softer, but real items also experience self-multiplication which can increase the 'size' of the bursts. Traditional NCC DT correction methods do not include the intrinsic (within burst) losses. We have proposed new forms of the traditional NCC Singles and Doubles DT correction factors. In this work, we apply Monte Carlo neutron pulse train analysis to investigate the functional form of the deadtime correction factors for an updating deadtime. Modeling is based on a high efficiency 3He neutron counter with short die-away time, representing an ideal 3He based detection system. The physics of dead time losses at low rates is explored and presented. It is observed that new forms are applicable and offer more accurate correction than the traditional forms.
Author : Mathieu Brener
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (959 download)
Download or read book The Effect of Delayed Neutrons and Detector Dead-time in Feynman Distribution Analysis written by Mathieu Brener and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I have explored the effect of delayed neutrons on neutron chains in a sub-critical nuclear system. Every fission has an approximately 0.7% chance of creating a delayed neutron that will go on to cause another fission. My hypothesis was that in systems with a very high sub-critical multiplication, there will be enough delayed neutrons created that they will in effect become a stronger starting neutron source than the original source. I used a point Monte-Carlo style simulation of sub-critical neutron chains to explore the physics of neutron chains. The simulation was designed to keep the same assumptions behind the Hage-Cifarelli derivation and Prasad-Snyderman formulation, to preserve the statistical variations in the list-mode data found in a physical experiment, and to be as simple as possible while maintaining accuracy. I present this method and benchmark it against both measured data and a theoretical model. I also use the model to simulate a Feynman Beta curve and 1/M approach-to-criticality experiments. I modified the simulation to take into account delayed neutrons and found that delayed neutrons have no measurable effect on a sub-critical systems for subcritical multiplication (M) less then 200. I wrote an algorithm to take into account detector dead-time with multiple detectors and found that increasing the number of detectors is the only effective method of compensating for dead-time effects. I investigated the minimum number of events needed for the analysis methods to produce accurate results and found that, for low values of M, there are statistical variations of the calculated multiplicity that will produce inaccurate results. For high values of M, the statistical variation is low, but an insufficient number of events will produce M-values that are inaccurately low.
Author : H. T. Heaton
Publisher :
ISBN 13 :
Total Pages : 36 pages
Book Rating : 4.3/5 (91 download)
Download or read book Use of an On-line Computer in Neutron Time-of-flight Measurements written by H. T. Heaton and published by . This book was released on 1970 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper describes the on-line data handling system at the NBS Electron Linear Accelerator facility as it is used for measuring neutron total cross sections by time-of-flight techniques.(Author).
Author :
Publisher :
ISBN 13 :
Total Pages : 28 pages
Book Rating : 4.:/5 (94 download)
Download or read book Implementation and Initial Testing of Advanced Processing and Analysis Algorithms for Correlated Neutron Counting written by and published by . This book was released on 2015 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to improve the accuracy and capabilities of neutron multiplicity counting, additional quantifiable information is needed in order to address the assumptions that are present in the point model. Extracting and utilizing higher order moments (Quads and Pents) from the neutron pulse train represents the most direct way of extracting additional information from the measurement data to allow for an improved determination of the physical properties of the item of interest. The extraction of higher order moments from a neutron pulse train required the development of advanced dead time correction algorithms which could correct for dead time effects in all of the measurement moments in a self-consistent manner. In addition, advanced analysis algorithms have been developed to address specific assumptions that are made within the current analysis model, namely that all neutrons are created at a single point within the item of interest, and that all neutrons that are produced within an item are created with the same energy distribution. This report will discuss the current status of implementation and initial testing of the advanced dead time correction and analysis algorithms that have been developed in an attempt to utilize higher order moments to improve the capabilities of correlated neutron measurement techniques.
Author :
Publisher :
ISBN 13 :
Total Pages : 7 pages
Book Rating : 4.:/5 (727 download)
Download or read book A Programmable Multichannel Correlation Module for Analyzing Neutron Multiplicities written by and published by . This book was released on 1989 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed a CAMAC module for analyzing neutron multiplicities. Reduction in dead time over previous methods has been made possible by providing independent detector channels. We have achieved a considerable reduction in circuitry by utilizing RAM and PROM integrated circuits in a nonstandard fashion. Along with specially developed algorithms, the module has been able to successfully unfold overlapping multiplicity chains for count rates varying over three orders of magnitude. 3 refs., 3 figs.
Download or read book Testing a Alternative Singles Rate Dead Time Correction Algorithm for Use in Neutron Multiplicity Analysis written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutron Multiplicity Analysis Tool written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I describe the capabilities of the EXCOM (EXcel based COincidence and Multiplicity) calculation tool which is used to analyze experimental data or simulated neutron multiplicity data. The input to the program is the count-rate data (including the multiplicity distribution) for a measurement, the isotopic composition of the sample and relevant dates. The program carries out deadtime correction and background subtraction and then performs a number of analyses. These are: passive calibration curve, known alpha and multiplicity analysis. The latter is done with both the point model and with the weighted point model. In the current application EXCOM carries out the rapid analysis of Monte Carlo calculated quantities and allows the user to determine the magnitude of sample perturbations that lead to systematic errors. Neutron multiplicity counting is an assay method used in the analysis of plutonium for safeguards applications. It is widely used in nuclear material accountancy by international (IAEA) and national inspectors. The method uses the measurement of the correlations in a pulse train to extract information on the spontaneous fission rate in the presence of neutrons from ([alpha], n) reactions and induced fission. The measurement is relatively simple to perform and gives results very quickly (d"1 hour). By contrast, destructive analysis techniques are extremely costly and time consuming (several days). By improving the achievable accuracy of neutron multiplicity counting, a nondestructive analysis technique, it could be possible to reduce the use of destructive analysis measurements required in safeguards applications. The accuracy of a neutron multiplicity measurement can be affected by a number of variables such as density, isotopic composition, chemical composition and moisture in the material. In order to determine the magnitude of these effects on the measured plutonium mass a calculational tool, EXCOM, has been produced using VBA within Excel. This program was developed to help speed the analysis of Monte Carlo neutron transport simulation (MCNP) data, and only requires the count-rate data to calculate the mass of material using INCC's analysis methods instead of the full neutron multiplicity distribution required to run analysis in INCC. This paper describes what is implemented within EXCOM, including the methods used, how the program corrects for deadtime, and how uncertainty is calculated. This paper also describes how to use EXCOM within Excel.
Author :
Publisher :
ISBN 13 :
Total Pages : 66 pages
Book Rating : 4.:/5 (94 download)
Download or read book Multiplicity Counting written by and published by . This book was released on 2015 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: This set of slides begins by giving background and a review of neutron counting; three attributes of a verification item are discussed: 240Pueff mass; [alpha], the ratio of ([alpha], n) neutrons to spontaneous fission neutrons; and leakage multiplication. It then takes up neutron detector systems - theory & concepts (coincidence counting, moderation, die-away time); detector systems - some important details (deadtime, corrections); introduction to multiplicity counting; multiplicity electronics and example distributions; singles, doubles, and triples from measured multiplicity distributions; and the point model: multiplicity mathematics.
Download or read book Systematic Effects in Neutron Coincidence and Multiplicity Counting written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Correlated neutron counting, including neutron coincidence and multiplicity counting, is an important tool in nuclear material accountancy verification. The accuracy of such measurements is of interest to the safeguards community because as the accuracy of NDA improves, the number of samples that are required to undergo destructive analysis (DA) decreases. The accuracy of a neutron mUltiplicity measurement can be affected by a number of variables. Monte Carlo neutron transport simulations with MCNPX have been performed to understand how the properties of the sample affect the count rate. These resultant count rates have been analyzed with the 'point model' in order to determine the effect on the deduced plutonium mass. The sample properties that have been investigated are density, sample position within the detector cavity, moisture content, isotopic composition, plutonium to total actinide ratio and heavy metal fraction. These parameters affect the Singles, Doubles and Triples count rates in different ways. In addition, different analysis methods use these measured quantities in different combinations, so that the final sensitivity of the 24°Pu mass to each parameter also depends on the analysis method used. For example, the passive calibration curve method only used the Doubles rate to produce the 24°Pu mass and so is not sensitive to changes in the Singles rate (to first order). The analysis methods considered here were passive calibration curve (non-multiplication corrected), known alpha (multiplication corrected) and multiplicity with known efficiency. The effects were studied on both a small mass MOX sample (1 g Pu) and a large MOX sample (6000 g Pu) both measured in high efficiency neutron multiplicity counters. In order to determine the final effect of each parameter it is necessary to know not only the sensitivity of the plutonium mass to that parameter, but also the range over which the parameter can realistically vary. Some estimates are given.
Download or read book Effects of (. Cap Alpha., N) Contaminants and Sample Multiplication on Statistical Neutron Correlation Measurements written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The complete formalism for the use of statistical neutron fluctuation measurements for the nondestructive assay of fissionable materials has been developed. This formalism includes the effect of detector deadtime, neutron multiplicity, random neutron pulse contributions from (.cap alpha., n) contaminants in the sample, and the sample multiplication of both fission-related and background neutrons.
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:
Download or read book The Ephithermal Neutron Multiplicity Counter Design and Performance Manual written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :
Publisher :
ISBN 13 :
Total Pages : 28 pages
Book Rating : 4.:/5 (967 download)
Download or read book Initial Results for Neutron Multiplicity Uncertainties written by and published by . This book was released on 2016 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the neutron multiplicity issue surrounding neutron detection in materials.
Author : Noel J. Drindak
Publisher :
ISBN 13 :
Total Pages : 42 pages
Book Rating : 4.:/5 (115 download)
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:
Author : Garrett Birkhoff
Publisher :
ISBN 13 :
Total Pages : 8 pages
Book Rating : 4.:/5 (553 download)
Download or read book Variable Dead Time Neutron Counter for tamper resistant measurements of spontaneous fission neutrons written by Garrett Birkhoff and published by . This book was released on 1972 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Paul J. Marano
Publisher :
ISBN 13 :
Total Pages : 124 pages
Book Rating : 4.:/5 (115 download)
Download or read book A Multiplicity Detector for Neutron Capture Measurements written by Paul J. Marano and published by . This book was released on 1989 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
