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Title: Detecting Illicit Radioactive Sources

Abstract

Specialized instruments have been developed to detect the presence of illicit radioactive sources that may be used by terrorists in radiation dispersal devices, so-called ''dirty bombs'' or improvised nuclear devices. This article discusses developments in devices to detect and measure radiation.

Authors:
; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab., Richland, WA (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
15010689
Report Number(s):
PNNL-SA-42028
Journal ID: ISSN 0031-9228; PHTOAD; TRN: US200502%%452
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics Today; Journal Volume: 57; Journal Issue: 11; Other Information: PBD: 1 Nov 2004
Country of Publication:
United States
Language:
English
Subject:
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; BOMBS; RADIATIONS; RADIATION DETECTION; RADIATION; HOMELAND SECURITY; INSTRUMENTATION; SENSORS

Citation Formats

McDonald, Joseph C., Coursey, Bert, and Carter, Michael. Detecting Illicit Radioactive Sources. United States: N. p., 2004. Web. doi:10.1063/1.1839375.
McDonald, Joseph C., Coursey, Bert, & Carter, Michael. Detecting Illicit Radioactive Sources. United States. doi:10.1063/1.1839375.
McDonald, Joseph C., Coursey, Bert, and Carter, Michael. 2004. "Detecting Illicit Radioactive Sources". United States. doi:10.1063/1.1839375.
@article{osti_15010689,
title = {Detecting Illicit Radioactive Sources},
author = {McDonald, Joseph C. and Coursey, Bert and Carter, Michael},
abstractNote = {Specialized instruments have been developed to detect the presence of illicit radioactive sources that may be used by terrorists in radiation dispersal devices, so-called ''dirty bombs'' or improvised nuclear devices. This article discusses developments in devices to detect and measure radiation.},
doi = {10.1063/1.1839375},
journal = {Physics Today},
number = 11,
volume = 57,
place = {United States},
year = 2004,
month =
}
  • The threat that weapons of mass destruction might enter the United States has led to a number of efforts for the detection and interdiction of nuclear, radiological, chemical, and biological weapons at our borders. There have been multiple deployments of instrumentation to detect radiation signatures to interdict radiological material, including weapons and weapons material worldwide.
  • Within the homeland security and emergency response communities, there is a need for a low-profile system to detect and locate radioactive sources. RadTrac has been developed at Argonne National Laboratory as an integrated system for the detection, localization, identification, and tracking of radioactive sources in real time. The system is based on a network of radiation detectors and advanced signal-processing algorithms. Features include video surveillance, automated tracking, easy setup, and logging of all data and images. This paper describes the advanced algorithms that were developed and implemented for source detection, localization, and tracking in real time. In the physio-spatial integrationmore » approach to source localization, counts from multiple detectors are processed according to the underlying physics linking these counts to obtain the probability that a source is present at any point in space. This information is depicted in a probability density function map. This type of depiction allows the results to be presented in a simple, easy-to-understand manner. It also allows for many different complicated factors to be accounted for in a single image as each factor is computed as a probability density in space. These factors include spatial limitations, variable shielding, directional detectors, moving detectors, and different detector sizes and orientations. The utility and versatility of this approach is described in further detail. Advanced signal-processing algorithms have also been incorporated to improve real-time tracking and to increase signal-to-noise ratios including temporal linking and energy binning. Measurements aimed at demonstrating the sensitivity improvements through the use of advanced signal-processing techniques were performed and are presented. Results of tracking weak sources (<100 {micro}Ci {sup 137}Cs) using four fixed-position detectors are presented.« less
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  • Simulation studies are presented regarding the performance of algorithms that localize point-like radioactive sources detected by a position sensitive portable radiation instrument (COCAE). The source direction is estimated by using the List Mode Maximum Likelihood Expectation Maximization (LM-ML-EM) imaging algorithm. Furthermore, the source-to-detector distance is evaluated by three different algorithms based on the photo-peak count information of each detecting layer, the quality of the reconstructed source image, and the triangulation method. These algorithms have been tested on a large number of simulated photons over a wide energy range (from 200 keV to 2 MeV) emitted by point-like radioactive sources locatedmore » at different orientations and source-to-detector distances.« less