Explosive Detection System Research Articles

Idaho Explosives Detection System

The Idaho Explosives Detection System was developed at the Idaho National Laboratory (INL) to respond to threats imposed by delivery trucks potentially carrying explosives into military bases. A full-scale prototype system has been built and is currently undergoing testing. The system consists of two racks, one on each side of a subject vehicle. Each rack includes a neutron generator and an array of NaI detectors. The two neutron generators are pulsed and synchronized. A laptop computer controls the entire system. The control software is easily operable by minimally trained staff. The system was developed to detect explosives in a medium size truck within a 5-min measurement time. System performance was successfully demonstrated with explosives at the INL in June 2004 and at Andrews Air Force Base in July 2004.

Assessing the impact of deterrence on aviation checked baggage screening strategies

This paper analyses checked baggage screening strategies that incorporate the effects of deterrence on explosive detection systems (EDSs) deployed at airports. Cost models for these strategies are presented that incorporate the cost of purchasing, operating, and maintaining an EDS, the number of checked bags available to be screened, and the numbers of selectees and non-selectees checked bags actually screened over a one-year period. The model also includes the effect of deterrence on the level of threat at an airport. The cost models provide a quantitative tool to assess the strategy of 100% screening of all checked bags, as set forth by the USA Aviation and Transportation Security Act. Comparing the expected direct cost per expected prevented attack to the expected cost of an aviation terrorist incident provides an indication of the cost effectiveness of 100% checked bag screening.

The key design parameters of checked baggage security screening systems in airports

In an effort to meet the checked baggage screening explosive detection deadline established by the Aviation and Transportation Security Act, the Transportation Security Administration placed hundreds of explosives detection system machines and thousands of explosives trace detection machines in airport check-in areas across the country as short-term solutions. To effectively integrate explosives detection system machines into the air transportation operations, numerous objectives must be balanced, including equipment cost, passenger and baggage demand, screening capacity, and security effectiveness. As a result, the Transportation Security Administration and its industry partners will need to increasingly rely on computer models, which offer the opportunity to examine the various complexities of the airport environment in a non-intrusive way, and to estimate the operational impact of new security equipment, policies, and procedures. While Transportation Security Administration, along with the airport community, is stimulating research in this area, it remains relatively undeveloped. Thus, the purpose of the research is to identify and evaluate the key design parameters of checked baggage screening, and to develop an analytical model that will determine the optimal number of explosives detection system equipment based on passenger demand levels and security protocols.

Gamma ray spectroscopy features for detection of small explosives

Thermal neutron capture techniques, as embodied in Thermal Neutron Analysis (TNA®) devices, provide a powerful tool for counter terrorism and environmental demilitarization. The common objective in both applications is the detection of explosives via their unique elemental constituents. In TNA, the primary explosive signature is the nitrogen concentration. Hydrogen is a secondary one. However, useful tertiary signatures exist in the full gamma-spectrum reflecting the explosive material itself and its surrounding. All these signatures, or spectra features, are derived from the analysis of the gamma-ray spectra collected by NaI detectors with a good energy resolution.This approach to the generation of explosive decision algorithms was incorporated in Ancore's Small Parcel Explosive Detection System (SPEDS) and other systems. The application described in this paper was the inspection airline passenger carry-on items such as laptop computers, briefcases, liquid bottles, etc., for the presence of small explosives.The feature analysis and the resulting excellent receiver operator characteristics are shown in the paper. The SPEDS was able to automatically detect less than 100g of explosives in carry-on items, with a low false alarm rate.

Measures of Effectiveness for Passenger-Baggage Security Screening

One of the most challenging tasks of the Aviation and Transportation Security Act of 2001 is to meet the goal of performing explosive detection system (EDS) screening on 100% of checked baggage by the end of calendar year 2002. Accomplishing this goal within the imposed deadline and within the typically tight space constraints of airport terminals will require significant changes in the way airlines and airports manage passengers and their baggage. One of the up-front keys to integrating 100% checked-baggage screening into airports is to identify realistic throughput rates of various EDS machines available to Transportation Security Administration (TSA) planners. Some of the issues associated with the implementation of EDS equipment are discussed, and an analysis is performed on the throughput of the equipment, using modeling and discrete event-simulation tools. One conclusion of the analysis is that a significant difference exists between the scan rate and the effective throughput rate for the InVision CTX5500, one of the tested EDS machines. This finding is extremely important for TSA planners, who are determining the number of EDS machines to buy and deploy at all 429 U.S. commercial airports. The deployments are based on passenger demand at peak hours of the day. Matching this relatively high-volume operation against the slow processing rate of a standalone EDS will generate large passenger queues unless multiple machines are installed to provide an acceptable level of customer (passenger) service. As a result, the effective throughput rate, not the machine scan rate, should be used in determining the number of EDS machines to install at a particular airport.

Explosives detection systems (EDS) for aviation security

The detection of explosives and illicit material for the purposes of aviation security is an important area for preventing terrorism and smuggling. A number of different methods of explosive detection have been developed in the past that can detect such material from a very small up to a very large quantity. For the purposes of aviation security, the checks are performed on passengers, their carry on luggage, checked baggage, and cargo containers. Similar technology is used in post-offices for detecting dangerous substances in mail. In this paper we review some of these technologies and in particular discuss the application of computers for the analysis of data and images generated from security equipment.

Slow takeoff [airport security

Before 9/11, air travel in the United States was plagued by delays. It still is. But now the stepped-up security in the aftermath of the hijackings has added congestion in terminals to the delays on the tarmac. Since the newly created Transportation Security Administration (TSA) took over US aviation security, US airports have had to be evacuated on more than 100 occasions and hundreds of flights have been recalled to terminals so that passengers could be rechecked. Equipment is a major concern. Explosives detection systems (EDS) are required to screen checked baggage, but aviation officials doubt they can be built and installed in time to meet the legislated 31 December 2002 deadline. Introducing the smaller, less expensive trace-explosive detectors would still require significant numbers of as-yet unbuilt and uninstalled machines. And operators trained to run all of these machines are in exceedingly short supply. To top it off, machines and personnel must somehow be paid for.

A comparison of decision-level sensor-fusion methods for anti-personnel landmine detection

We present the sensor-fusion results obtained from measurements within the European research project ground explosive ordinance detection (GEODE) system that strives for the realisation of a vehicle-mounted, multi-sensor, anti-personnel landmine-detection system for humanitarian de-mining. The system has three sensor types: a metal detector (MD), an infrared camera (IR), and a ground penetrating radar (GPR). The output of the sensors is processed to produce confidence levels on a grid covering the test-bed. A confidence level expresses a confidence or belief in a landmine detection on a certain position. The grid with confidence levels is the input for the decision-level sensor-fusion and provides a co-registration of the sensors. The applied fusion methods are naive Bayes' approaches, Dempster–Shafer theory, fuzzy probabilities, a rule-based method, and voting techniques. To compare fusion methods and to analyse the capacity of a method to separate landmines from the background on the basis of the output of different sensors, we provide an analysis of the different methods by viewing them as discriminant functions in the sensor confidence space. The results of experiments on real sensor data are evaluated with the leave-one-out method.

Design and evaluation of a TNA explosive-detection system to screen carry-on luggage

Thermal neutron analysis (TNA) technology has been used for the non-destructive detection of explosives. The system uses a relatively weak 252Cf neutron source (1.03·107 n/s) and two 3"×3" NaI(Tl) detectors. The presence of explosives is confirmed via detection of the 10.83 MeV prompt gamma-ray associated with nitrogen decay. The MCNP4A code was used to simulate the neutron and gamma transport through the system. The thermal neutron flux in the activation position was measured using gold and indium foils. The measured thermal neutron flux was lower, by not more than 9.5%, than that of simulation. In this report the results of the preliminary tests on the system are described.

Thermal neutron analysis (TNA) explosive detection based on electronic neutron generators

Thermal neutron analysis explosive detection systems have been developed and demonstrated for inspection of checked airline baggage and for detection of buried land mines. Thermal neutrons from a moderated neutron source impinge on the inspected object, and the resulting capture gamma ray signatures provide detection information. Isotopic neutron sources, e.g. 252Cf, are compact, economical and reliable, but they are subject to the licensing requirements, safety concerns and public perception problems associated with radioactive material. These are mitigated by use of an electronic neutron generator — an ion accelerator with a target producing neutrons by a nuclear reaction such as D(d, n) 3He or 9Be(d, n) 10B. With suitable moderator designs based on neutron transport codes, operational explosive detection systems can be built and would provide effective alternatives to radioactive neutron sources. Calculations as well as laboratory and field experience with three generator types will be presented.

In Situ Detection and Identification of Trace Explosives by Raman Microscopy

Abstract The innovative design of the newly developed Renishaw Raman Microscope system and its application to the in situ detection and identification of plastic explosives contained in fingerprint samples are presented. Raman microscopy is a nondestructive inspection method. Our experimental results show that Raman spectra and Raman band images can be obtained from explosive particles as small as 1 µm3 in size or 1 picogram in mass. After exploring the full potential of the Raman microscopic technique, the aim of this research is to develop a real-time and field-deployable plastic explosive detection system.

Technical updates from the TNA operations program

The operation of the Thermal Neutron Analysis (TNA) Explosive Detection Systems in a number of airports throughout the world has yielded a wealth of information. These devices have been deployed to detect explosives in checked luggage before they reach the aircraft. Data from over 1 million bags have been collected, and the TNA operation has resulted in one arrest and the apprehension of illicit materials. Distributions of unusual elements, elemental and physical densities of suitcases for various sites are given. These data are critical to the estimation of the performance of new systems based on advanced X-ray or neutron techniques. Several cases of particular importance to TNA were studied. A sample application of this distribution data to the evaluation of proposed changes to the TNA is described. Optimization of the cavity structure and the neutron moderator design to reduce hydrogen backgrounds was performed via computer modeling.

Neural networks

Just four years ago, the only widely reported commercial application of neural network technology outside the financial industry was the airport baggage explosive detection system [27] developed at Science Applications International Corporation (SAIC). Since that time scores of industrial and commercial applications have come into use, but the details of most of these systems are considered corporate secrets and are shrouded in secrecy. This hastening trend is due in part to the availability of an increasingly wide array of dedicated neural network hardware. This hardware is either in the form of accelerator cards for PCs and workstations or a large number of integrated circuits implementing digital and analog neural networks either currently available or in the final stages of design

Design and calibration of pulsed vapor generators for 2,4,6-trinitrotoluene, cyclo-1,3,5-trimethylene-2,4,6-trinitramine, and pentaerythritol tetranitrate

Computer-controlled pulsed explosive vapor generators for 2,4,6-trinitrotoluene (TNT), cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), and pentaerythritol (PETN) were built and calibrated to support an independent validation and verification facility for explosive detection systems for the Federal Aviation Administration at the Idaho National Engineering Laboratory. The explosive vapor generators will be used as quantitative vapor standards to establish the lower limits of detection of explosive detection systems. The generators were constructed using pure explosive suspended on quartz beads which were then loaded into a stainless steel tube. The tube was coiled and placed into a temperature-controlled chamber. A carrier gas (ultrapure air) was passed through the coil to carry the explosive molecules. The generators are capable of delivering a pulse of varying explosive mass through the control of coil temperature, airflow rate, and pulse width. Preliminary calibrations have been completed in the picogram to nanogram range using an ion mobility spectrometer as the calibrating instrument. 8 refs., 5 figs., 6 tabs.

Advances in accelerator based explosives detection systems

Great strides were made over the last several years in the development of nuclear-based explosive detection systems (EDS). Charged particle accelerators are playing an important role as the preferred source of interrogating radiation. Thermal neutron analysis, based on thermal neutron capture in nitrogen, is the most mature of the explosive detection techniques. It can employ a 252Cf radioisotope or a deuteron accelerator generating neutrons via (d, D), (d, Be) or even (d, T) reactions combined with a neutron moderator. Fast neutron analysis techniques, based on the (n,n'γ) processes for elemental discrimination, use deuteron accelerators to generate high energy neutrons, ≤, 14 MeV, continuous or pulsed. The role and experience of various accelerators in EDS are discussed.

Designing an effective international aviation security system

International reform of aviation security is vital in the light of continuing vulnerability to sabotage bombing and other threats. Radical innovation and broad vision are needed to design an effective system, but it is feasible. (Many predicted that the US anti‐hijack measures introduced in 1972 would be unworkable: in fact they were highly successful.) The author argues for enhanced security coordination at national and international levels, especially in the fields of counter‐terrorism intelligence, radically enhanced explosive detection systems, airport security procedures, and security staff quality, and a major programme to help poorer countries to upgrade their airport security.

Detection of Trace Explosive Evidence by Ion Mobility Spectrometry

Abstract The continuing threat of worldwide terrorism has prompted the need for new and innovative explosives detection systems. As part of an ongoing research effort, the FBI Laboratory has been evaluating new technology and the innovative adaptation of existing technology for use in counterterrorism and counternarcotics investigations. We have been examining the application of ion mobility spectrometry (IMS), for its role in explosives detection. The explosives residue is collected on a membrane filter by a special attachment on a household vacuum. Subsequent thermal desorption and analysis requires 5 s. Experimental results have determined the limits of detection for most common explosives to be approximately 200 pg. The vacuum sampling method permits the collection of trace physical evidence transferred to hands or surfaces through contact or post blast residue. The persistence of explosives on hands and transfer to other surfaces has been examined. Post-blast residue of NG was detected on fragments of improvised explosive devices constructed with double-based smokeless powder. Post-blast residue from C-4, Deta Sheet, SEMTEX, and ammonium nitrate explosives have also been detected on items of forensic and evidentiary value.

空港における爆薬検知法の開発

空港における爆薬検知法の開発

A transient explosive vapor generator based on capillary gas chromatography

Abstract A vapor generator is described which produces transient clouds of pure explosive vapor. This vapor generator is based upon a commercially available capillary gas chromatograph. By using a gas chromatograph, and generating transient vapor clouds, a higher purity of explosive vapor is obtainable than was previously possible. The chemical composition of the vapor generator was confirmed by both gas chromatography/mass spectrometry and by ion mobility spectrometry. Although this research only involved the generation of dinitrotoluene (DNT), trinitrotoluene (TNT) and 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) vapors, this system should be able to generate vapors of any volatile explosive. The vapor generator was successfully used in comparative testing of four commercially available explosive vapor detection systems.

Explosive detection systems: Oral statement on behalf of the airport operators council international and the American association of airport executives

Explosive detection systems: Oral statement on behalf of the airport operators council international and the American association of airport executives