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Title: Point Source Detection and Characterization for Vehicle Radiation Portal Monitors

Abstract

Many international border crossings presently screen cargo for illicit nuclear material using radiation portal monitors that measure the gamma ray and/or neutron flux emitted by vehicles. The fact that many target sources have a point-like geometry can be exploited to detect sub-threshold sources and filter out benign sources that frequently possess a distributed geometry. This report describes a two-step process, which has the potential to complement other alarm algorithms, for detecting and characterizing point sources. The first step applies a matched filter whereas step two uses maximum likelihood estimation. In a base-case simulation, matched filtering detected a 250-cps source injected onto a white-noise background at a 95-percent detection probability and a 0.003 false alarm probability. For the same simulation, the probability of success for the maximum likelihood estimation technique performed well at source strengths of 250 and 400 cps. These simulations provided a best-case feasibility study for this technique, which will be extended to experimental data that possess false point-source signatures resulting from background shielding caused by vehicle design and cargo distribution.

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
877561
Report Number(s):
PNNL-SA-44882
Journal ID: ISSN 0018-9499; IETNAE; 400904120; TRN: US0601593
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Nuclear Science; Journal Volume: 52; Journal Issue: 6 PT 2
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CARGO; DETECTION; RADIATION MONITORS; NEUTRON DETECTION; POINT SOURCES; PROBABILITY; GAMMA DETECTION; SHIELDING; VEHICLES; COMPUTERIZED SIMULATION

Citation Formats

Runkle, Robert C., Mercier, Terre M., Anderson, Kevin K., and Carlson, Deborah K.. Point Source Detection and Characterization for Vehicle Radiation Portal Monitors. United States: N. p., 2005. Web. doi:10.1109/TNS.2005.862910.
Runkle, Robert C., Mercier, Terre M., Anderson, Kevin K., & Carlson, Deborah K.. Point Source Detection and Characterization for Vehicle Radiation Portal Monitors. United States. doi:10.1109/TNS.2005.862910.
Runkle, Robert C., Mercier, Terre M., Anderson, Kevin K., and Carlson, Deborah K.. Thu . "Point Source Detection and Characterization for Vehicle Radiation Portal Monitors". United States. doi:10.1109/TNS.2005.862910.
@article{osti_877561,
title = {Point Source Detection and Characterization for Vehicle Radiation Portal Monitors},
author = {Runkle, Robert C. and Mercier, Terre M. and Anderson, Kevin K. and Carlson, Deborah K.},
abstractNote = {Many international border crossings presently screen cargo for illicit nuclear material using radiation portal monitors that measure the gamma ray and/or neutron flux emitted by vehicles. The fact that many target sources have a point-like geometry can be exploited to detect sub-threshold sources and filter out benign sources that frequently possess a distributed geometry. This report describes a two-step process, which has the potential to complement other alarm algorithms, for detecting and characterizing point sources. The first step applies a matched filter whereas step two uses maximum likelihood estimation. In a base-case simulation, matched filtering detected a 250-cps source injected onto a white-noise background at a 95-percent detection probability and a 0.003 false alarm probability. For the same simulation, the probability of success for the maximum likelihood estimation technique performed well at source strengths of 250 and 400 cps. These simulations provided a best-case feasibility study for this technique, which will be extended to experimental data that possess false point-source signatures resulting from background shielding caused by vehicle design and cargo distribution.},
doi = {10.1109/TNS.2005.862910},
journal = {IEEE Transactions on Nuclear Science},
number = 6 PT 2,
volume = 52,
place = {United States},
year = {Thu Dec 01 00:00:00 EST 2005},
month = {Thu Dec 01 00:00:00 EST 2005}
}
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