Explosives Detection Using Magnetic And Nuclear Resonance Techniques

Nuclear quadrupole resonance (NQR) a highly promising new technique for bulk explosives detection: relatively inexpensive, more compact than NMR, but with considerable selectivity. Since the NQR frequency is insensitive to long-range variations in composition, mixing explosives with other materials, such as the plasticizers in plastic explosives, makes no difference. The NQR signal strength varies linearly with the amount of explosive, and is independent of its distribution within the volume monitored. NQR spots explosive types in configurations missed by the X-ray imaging method. But if NQR is so good, why it is not used everywhere? Its main limitation is the low signal-to-noise ratio, particularly with the radio-frequency interference that exists in a field environment, NQR polarization being much weaker than that from an external magnetic field. The distinctive signatures are there, but are difficult to extract from the noise. In addition, the high selectivity is partly a disadvantage, as it is hard to build a multichannel system necessary to cover a wide range of target substances. Moreover, substances fully screened by metallic enclosures, etc. are difficult to detect. A workshop was held at St Petersburg in July 2008 in an attempt to solve these problems and make NQR the universal technique for the detection of bombs regardless of type. This book presents the essentials of the papers given there.

Detection of concealed explosives is a notoriously difficult problem, and many different approaches have been proposed to solve this problem. Nuclear quadrupole resonance (NQR) is unique in many ways. It operates in a safe AM radio frequency range, and it can remotely detect unique “fingerprint” (NQR spectrum) of many explosives, such as TNT or RDX. As such, the detection of target does not depend on the shape or material of the container, or the presence of metallic object such as triggers etc. Spectra of chemically similar compounds differ enough that their presence never causes interference or false alarms. Unfortunately, widespread use is prevented due to low sensitivity, radiofrequency interference from the noisy environment, and inability to detect liquid explosives. This book presents current state of the art of the attempts to overcome NQR sensitivity problem, either by increasing the strengths of signals generated, or by increasing the specificity of the technique through a better understanding of the factors that affect the quadrupolar parameters of specific explosives. The use of these specific quadrupolar parameters is demonstrated on signal processing techniques that can detect weak signals, which are hidden in a noisy background. The problem of differentiation of liquid explosives and benign liquids in closed containers is approached by measurements of different nuclear magnetic resonance (NMR) parameters. As shown, a couple of solutions has reached a prototype stage and could find their use in a near future.

Detection of Bulk Explosives: Advanced Techniques against Terrorism contains reviews of: existing and emerging bulk explosives detection techniques; scientific and technical policy of the Federal Border Service of the Russian Federation; challenges in application and evaluation of EDS systems for aviation security; multi-sensor approach to explosives detection. There are also reports devoted to the following individual explosive detection techniques: X-ray systems in airports; neutron in, gamma out techniques; neutron and gamma backscattering; nuclear quadruple resonance, including remote NQR; sub-surface radars; microwave scanners; laser-induced burst spectroscopy (LIBS); acoustic sensors; nonlinear location (NUD); systems for localization and destruction of explosive objects.

The detection of hidden explosives has become an issue of utmost importance in recent years. While terrorism is not new to the international community, recent terrorist attacks have raised the issue of detection of explosives and have generated a great demand for rapid, sensitive and reliable methods for detecting hidden explosives. Counterterrorist Detection Techniques of Explosives covers recent advances in this area of research including vapor and trace detection techniques (chemiluminescence, mass spectrometry, ion mobility spectrometry, electrochemical methods and micromechanical sensors, such as microcantilevers) and bulk detection techniques (neutron techniques, nuclear quadrupole resonance, x-ray diffraction imaging, millimeter-wave imaging, terahertz imaging and laser techniques). This book will be of interest to any scientists involved in the design and application of security screening technologies including new sensors and detecting devices which will prevent the smuggling of bombs and explosives. * Covers latest advances in vapor and trace detection techniques and bulk detection techniques* Reviews both current techniques and those in advanced stages of development* Techniques that are described in detail, including its principles of operation, as well as its applications in the detection of explosives

Existing and Potential Standoff Explosives Detection Techniques examines the scientific techniques currently used as the basis for explosives detection and determines whether other techniques might provide promising research avenues with possible pathways to new detection protocols. This report describe the characteristics of explosives, bombs, and their components that are or might be used to provide a signature for exploitation in detection technology; considers scientific techniques for exploiting these characteristics to detect explosives and explosive devices; discusses the potential for integrating such techniques into detection systems that would have sufficient sensitivity without an unacceptable false-positive rate; and proposes areas for research that might be expected to yield significant advances in practical explosives and bomb detection technology in the near, mid, and long term.

This book is about improving prohibited substances detection using the nuclear quadrupole resonance (NQR) technique at security checkpoints. The book proposes multiple signal processing and analysis techniques for improving detection of dangerous or contraband substances, such as explosives, narcotics, or toxic substances. Also, several hardware solutions are described and implemented in a custom-designed NQR spectrometer. A new approach to NQR signal detection is introduced using artificial intelligence/deep learning techniques. The book will be useful for for researchers and practitioners in the areas of electrical engineering, signal processing and analysis, applied spectroscopy, as well as for security or laboratory equipment manufacturers.

This ARW is the third NATO-sponsored workshop on Explosives Detection and Humanitarian Demining. The previous events were • Detection and Destruction of Anti-Personnel Landmines Moscow, 1997 • Explosives Detection and Decontamination of the Environment Prague, 1997. Over the last decade applied research in Humanitarian Demining has made progress to some extend, but according to the tremendous tasks of Demining and the lack of scientific methods for practical detection of explosive devices, research activities are still of the same importance than ever before. Concerning countermeasures against terrorism the detection of explosives is one of the keyfactors, but the practical applications are not sufficient solved. An international exchange of research results are therefore urgent, to find out the most promising measures for application. The coincidence of this ARW and the terrible disaster of New York and Washington may demonstrate the importance of this task. In consequence the explosive device detection technologies can make a major contribution to collective, family and individual security. In developed countries, these technologies provide a strong deterrent and preventative measure against terrorist threats. In less developed regions, they can improve individual, institutional and state security, lessening the insecurity that motivates many terrorists acts. The elimination of landmine threats is just one of many ways of achieving this. However our attempts to meet the extremely difficult technical challenges posed by landmine and UXO contamination are inevitably leading us to new technological approaches.

Field Detection Technologies For Explosives Explosives are historically the weapons that have been most frequently used against civilians by terrorist organisations. In the past few years, the use of explosives by terrorist groups has cost the lives of more people than the combination of all other attacks, including the use of weapons of mass destruction (chemical, biological and nuclear weapons). Early detection of these substances is one of the most effective ways to prevent attacks using explosives from occurring. Fast and reliable equipment to detect the presence of explosives and explosive devices is critical to fighting terrorism. Written in a style that makes complicated technologies easy to understand, this book covers the principles, instrumentation and applications of current technologies used to detect explosives in the field. Both trace detection technologies and bulk detection technologies are discussed. The section on trace detection technologies includes chapters on ion mobility spectrometry, piezoelectric sensors, chemiluminescence-based detectors, polymer-based technologies and mass spectrometry. It also discusses detection requirements, methodologies used for detector evaluation, and sampling technologies. The section on bulk detection contains chapters on x-ray, millimeter wave imaging, neutron and nuclear quadrupoie resonance technologies. This volume introduces the basic concepts of commonly used explosives detection technologies and is an essential resource for novice or more experienced personnel working in the explosives detection field as well as those with a general interest in this important subject. Features Discusses all aspects of commonly used field detection technologies. Reviews detection requirements and explosives sampling methods. Describes specific instruments used for field detection applications, such as at airports, harbours and border crossings. Includes a summary of common explosives and their important properties for easy reference. Provides an introduction to data fusion and receiver operating characteristic methods, both of which have recently received significant attention in the field of explosives detection. Book jacket.