Expected Precision for Neutron Multiplicity Assay Using Higher Order Moments PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Expected Precision for Neutron Multiplicity Assay Using Higher Order Moments PDF full book. Access full book title Expected Precision for Neutron Multiplicity Assay Using Higher Order Moments by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages : 11
Book Description
This paper reports on the development of a new Figure of Merit code that can calculate the expected precision in neutron multiplicity assay using higher order moments. The code is used to provide a first look at the quadruple coincidence count rate and its expected precision. The results are good enough to warrant further study of potential applications of quadruple (quad) coincidences for large multiplying plutonium items. Also, the new code makes it possible to estimate the multiplicity assay precision if only randomly-triggered moments are used. This approach is described briefly, along with the current status of the investigation.
Author: Publisher: ISBN: Category : Languages : en Pages : 11
Book Description
This paper reports on the development of a new Figure of Merit code that can calculate the expected precision in neutron multiplicity assay using higher order moments. The code is used to provide a first look at the quadruple coincidence count rate and its expected precision. The results are good enough to warrant further study of potential applications of quadruple (quad) coincidences for large multiplying plutonium items. Also, the new code makes it possible to estimate the multiplicity assay precision if only randomly-triggered moments are used. This approach is described briefly, along with the current status of the investigation.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
This document is intended to serve as a comprehensive applications guide to passive neutron multiplicity counting, a new nondestructive assay (NDA) technique developed over the past ten years. The document describes the principles of multiplicity counter design, electronics, and mathematics. Existing counters in Department of Energy (DOE) facilities are surveyed, and their operating requirements and procedures and defined. Current applications to plutonium material types found in DOE facilities are described, and estimates of the expected assay precision and bias are given. Lastly, guidelines for multiplicity counter selection and procurement are summarized. The document also includes a detailed collection of references on passive neutron coincidence and multiplicity publications over the last ten to fifteen years.
Author: Publisher: ISBN: Category : Languages : en Pages : 6
Book Description
This paper describes a measurement of the precision of the new active-neutron-multiplicity assay technique, which is currently under development for bulk uranium containing kilogram quantities of 235U. The new technique analyzes neutron multiplicity data collected with a coincidence counter outfitted with AmLi neutron sources. We report on the observed assay precision and the implications for field use of the technique.
Author: Publisher: ISBN: Category : Languages : en Pages : 8
Book Description
Accurate assay of most common plutonium samples was the development goal for the nondestructive assay technique of neutron multiplicity counting. Over the past 20 years the technique has been proven for relatively pure oxides and small metal items. Unfortunately, the technique results in large biases when assaying large metal items. Limiting assumptions, such as unifoh multiplication, in the point model used to derive the multiplicity equations causes these biases for large dense items. A weighted point model has been developed to overcome some of the limitations in the standard point model. Weighting factors are detemiined from Monte Carlo calculations using the MCNPX code. Monte Carlo calculations give the dependence of the weighting factors on sample mass and geometry, and simulated assays using Monte Carlo give the theoretical accuracy of the weighted-point-model assay. Measured multiplicity data evaluated with both the standard and weighted point models are compared to reference values to give the experimental accuracy of the assay. Initial results show significant promise for the weighted point model in reducing or eliminating biases in the neutron multiplicity assay of metal items. The negative biases observed in the assay of plutonium metal samples are caused by variations in the neutron multiplication for neutrons originating in various locations in the sample. The bias depends on the mass and shape of the sample and depends on the amount and energy distribution of the ([alpha], n) neutrons in the sample. When the standard point model is used, this variable-multiplication bias overestimates the multiplication and alpha values of the sample, and underestimates the plutonium mass. The weighted point model potentially can provide assay accuracy of H"% (1 [sigma]) for cylindrical plutonium metal samples
Author: Publisher: ISBN: Category : Languages : en Pages : 17
Book Description
This paper describes the use of a new figure of merit code that calculates both bias and precision for coincidence and multiplicity counting, and determines the optimum regions for each in waste assay applications. A tunable multiplicity approach is developed that uses a combination of coincidence and multiplicity counting to minimize the total assay error. An example is shown where multiplicity analysis is used to solve for mass, alpha, and multiplication and tunable multiplicity is shown to work well. The approach provides a method for selecting coincidence, multiplicity, or tunable multiplicity counting to give the best assay with the lowest total error over a broad spectrum of assay conditions.
Author: David E. Robertson Publisher: SPIE-International Society for Optical Engineering ISBN: Category : Technology & Engineering Languages : en Pages : 196
Author: 
Author: 
Author: 
Author: 
Author: 
Author: 
Author: W. H. Geist
Author: 
Author: David E. Robertson
Author: 
Author: Doug Reilly