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Title: Germanium Detectors in Homeland Security at PNNL

Abstract

Neutron and gamma-ray detection is used for non-proliferation and national security applications. While lower energy resolution detectors such as NaI(Tl) have their place, high purity germanium (HPGe) also has a role to play. A detection with HPGe is often a characterization due to the very high energy resolution. However, HPGe crystals remain small and expensive leaving arrays of smaller crystals as an excellent solution. PNNL has developed two similar HPGe arrays for two very different applications. One array, the Multisensor Aerial Radiation Survey (MARS) detector is a fieldable array that has been tested on trucks, boats, and helicopters. The CASCADES HPGe array is an array designed to assay samples in a low background environment. The history of HPGe arrays at PNNL and the development of MARS and CASCADES will be detailed in this paper along with some of the other applications of HPGe at PNNL.

Authors:
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1233774
Report Number(s):
PNNL-SA-107425
Journal ID: ISSN 1742-6588
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physics. Conference Series; Journal Volume: 606; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
HPGe; arrays; homeland security

Citation Formats

Stave, Sean C. Germanium Detectors in Homeland Security at PNNL. United States: N. p., 2015. Web. doi:10.1088/1742-6596/606/1/012018.
Stave, Sean C. Germanium Detectors in Homeland Security at PNNL. United States. doi:10.1088/1742-6596/606/1/012018.
Stave, Sean C. Fri . "Germanium Detectors in Homeland Security at PNNL". United States. doi:10.1088/1742-6596/606/1/012018.
@article{osti_1233774,
title = {Germanium Detectors in Homeland Security at PNNL},
author = {Stave, Sean C.},
abstractNote = {Neutron and gamma-ray detection is used for non-proliferation and national security applications. While lower energy resolution detectors such as NaI(Tl) have their place, high purity germanium (HPGe) also has a role to play. A detection with HPGe is often a characterization due to the very high energy resolution. However, HPGe crystals remain small and expensive leaving arrays of smaller crystals as an excellent solution. PNNL has developed two similar HPGe arrays for two very different applications. One array, the Multisensor Aerial Radiation Survey (MARS) detector is a fieldable array that has been tested on trucks, boats, and helicopters. The CASCADES HPGe array is an array designed to assay samples in a low background environment. The history of HPGe arrays at PNNL and the development of MARS and CASCADES will be detailed in this paper along with some of the other applications of HPGe at PNNL.},
doi = {10.1088/1742-6596/606/1/012018},
journal = {Journal of Physics. Conference Series},
number = 1,
volume = 606,
place = {United States},
year = {Fri May 01 00:00:00 EDT 2015},
month = {Fri May 01 00:00:00 EDT 2015}
}
  • Neutron and gamma-ray detection is used for non-proliferation and national security applications. While lower energy resolution detectors such as NaI(Tl) have their place, high purity germanium (HPGe) also has a role to play. A detection with HPGe is often a characterization due to the very high energy resolution. However, HPGe crystals remain small and expensive leaving arrays of smaller crystals as an excellent solution. PNNL has developed two similar HPGe arrays for two very different applications. One array, the Multisensor Aerial Radiation Survey (MARS) detector is a fieldable array that has been tested on trucks, boats, and helicopters. The CASCADESmore » HPGe array is an array designed to assay samples in a low background environment. The history of HPGe arrays at PNNL and the development of MARS and CASCADES will be detailed in this paper along with some of the other applications of HPGe at PNNL.« less
  • No abstract prepared.
  • Preventing and protecting against catastrophic terrorism is a complex and dynamic challenge. Small groups or individuals can use advanced technology to cause massive destruction, and the rapid pace of technology and ease of information dissemination continually gives terrorists new tools. A 100% defense is not possible. It's a numbers problem--there are simply too many possible targets to protect and too many potential attack scenarios and adversaries to defend against. However, science and technology (S&T) is a powerful force multiplier for defense. We must use S&T to get ahead of the game by making terrorist attacks more difficult to execute, moremore » likely to be interdicted, and less devastating in terms of casualties, economic damage, or lasting disruption. Several S&T areas have potential to significantly enhance homeland security efforts with regard to detecting radiation, pathogens, explosives, and chemical signatures of weapons activities. All of these areas require interdisciplinary research and development (R&D), and many critically depend on advances in materials science. For example, the science of nuclear signatures lies at the core of efforts to develop enhanced radiation detection and nuclear attribution capabilities. Current radiation detectors require cryogenic cooling and are too bulky and expensive. Novel signatures of nuclear decay, new detector materials that provide high resolution at ambient temperatures, and new imaging detectors are needed. Such technologies will improve our ability to detect and locate small, distant, or moving sources and to discriminate threat materials from legitimate sources. A more complete understanding of isotopic ratios via secondary ion mass spectrometry (SIMS), NanoSIMS, or yet-to-be-developed technologies is required to elucidate critical characteristics of nuclear materials (e.g., isotopics, age, reprocessing) in order to identify their source and route history. S&T challenges abound in the biodefense arena as well. Improved biodetectors are needed--autonomous instruments that continuously monitor the environment for threat pathogens, promptly alert authorities in the event of a positive detection, and have an extremely low false alarm rate. Because many threat pathogens are endemic to various regions of the world, the natural microbial environment must be characterized so that background detections can be distinguished from a deliberate release. In addition, most current detection approaches require an a priori knowledge of the pathogens of concern and thus won't work in the face of a new, naturally occurring disease, such as a mutated avian influenza that effects humans, or a deliberately manipulated organism. Thus, we must move from species-specific detection to function-based detection based on a fundamental understanding of the mechanisms and genetic markers of infectivity, pathogenicity, antibiotic resistance, and other traits that distinguish a harmful organism from an innocuous one. Last but not least, new vaccines and treatments are needed, which in turn require in-depth understanding of cellular surfaces, protein folding, and myriad nano-bio aspects of host-pathogen interactions. Much attention is being devoted to countering weapons-of-mass-destruction terrorism, since Al-Qaeda and other terrorist groups have repeatedly stated their intention to acquire and use nuclear, chemical, or biological weapons. However, terrorists in Iraq and elsewhere continue to wreak havoc using improvised explosive devices. Thus, there is a pressing security need for better methods for detecting explosive materials and devices. Transformational S&T such as pulsed fast-neutron analysis or terahertz spectroscopy for material- and element-specific imaging offer the promise of greatly improved explosive detection. For bioscience-based approaches, the development of highly multiplexed transducer arrays and molecular recognition methods that mimic biological systems would similarly provide the foundation for vastly improved capabilities. Likewise, new materials and technologies are needed for the detection of chemical signatures of weapons activities. One grand challenge is the detection and characterization of chemical effluents indicative of weapons production, either biological, chemical, or nuclear. Ideally, one would like to be able to detect such chemical signatures remotely, via satellite or other high-altitude platform. To do so, one must know what chemicals, singly or in combination, would be produced in various production processes, how they would behave in the environment, and how those chemicals, their precursors, and degradation products could be sampled.« less
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  • Strontium-90 is one of the most hazardous materials managed by agencies charged with protecting the public from radiation. Traditional radiometric methods have been limited by low sample throughput and slow turnaround times. Mass spectrometry offers the advantage of shorter analysis times and the ability to measure samples immediately after processing, however conventional mass spectrometric techniques are susceptible to molecular isobaric interferences that limit their overall sensitivity. In contrast, accelerator mass spectrometry is insensitive to molecular interferences and we have therefore begun developing a method for determination of {sup 90}Sr by accelerator mass spectrometry. Despite a pervasive interference from {sup 90}Zr,more » our initial development has yielded an instrumental background of {approx} 10{sup 8} atoms (75 mBq) per sample. Further refinement of our system (e.g., redesign of our detector, use of alternative target materials) is expected to push the background below 10{sup 6} atoms, close to the theoretical limit for AMS. Once we have refined our system and developed suitable sample preparation protocols, we will utilize our capability in applications to homeland security, environmental monitoring, and human health.« less