摘要:

The status of bulk explosive detection techniques based on nuclear interrogation methods is reviewed. The desirable characteristics of an operational system capable of meeting the requirements for civil aviation security are compared with what can be expected from nuclear-based techniques. The comparison is limited to those techniques that utilize penetrating neutron and photon probes on the target elements of explosives most likely to be encountered in the airport scenario. The physical properties of a relevant group of explosives are surveyed for unique characteristics that could provide detectable signatures to nuclear-based techniques. A survey of the accessible reactions and their relative detection sensitivities are tabulated for a selection of practical interrogating probes. Some results obtained with systems currently under development are reported.

ISSN:0737-0652    

DOI:10.1080/07370658608011351

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The paper consists of two parts. In the first part, the rationale and considerations leading to the development of an explosives vapour detector suitable for screening suspect aircraft for hidden bombs is discussed. The detector is based on GC/ECD and consists of two components, the main analysing unit and a detachable sampling probe. A number of prototype detectors was fabricated at the National Research Council of Canada (NRC), and, after laboratory and field trials, the design became the basis of a commercially produced model.

ISSN:0737-0652    

DOI:10.1080/07370658608011352

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

New vapor pressure data is presented for RDX, PETN, TNT, nitroglycerin, and ammonium nitrate. By comparison with the data of previous workers, it has been possible to calculate global vapor pressure expressions which are valid over a wide range of temperatures.

ISSN:0737-0652    

DOI:10.1080/07370658608011353

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

For most explosives vapor detection scenarios, the lower detection limit (LDL) requirements are at part-per-trillion (ppt) concentration levels. Further sensitivity constraints are imposed on the detector modules by attendant sampling dilution and inefficient transport of explosives vapor molecules through the detection system sample train. Efficient transport and large preconcentration factors (≃ 100,000) can be achieved simultaneously by using a liquid sampling module, comprising a wetted-wall column in the sample train. Liquid sampling modules are interfaced most effectively to wet-chemical detectors. The transport and preconcentration processor introduces a 60-s or longer lag to the overall system time rate-of-response depending on the preconcentration requirements. Despite the long delay time of liquid preconcentrators and the relatively slow rate-of-response time and limited sensitivity of wet-chemical vapor detectors, it appears that their use is feasible for some applications. For example, those detectors with a liquid transport and preconcentration sample train can monitor the atmosphere within enclosures such as rooms, buildings, etc. The inlet to the sample can be located at some convenient and effective point, e.g., in the main air conditioning or ventilation duct upstream of the blower.

ISSN:0737-0652    

DOI:10.1080/07370658608011354

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The vapor components of several water gel explosives have been characterized using Pt-wire preconcentration/capillary gas chromatography; concentration of headspace vapors on Tenax-GC with thermal desorption capillary gas chromatography/mass spectrometry; and liquid chromatography with Thermal Energy Analyzer detection. In addition to normal sensitizing agents almost all of the water gel explosives were found to be contaminated with ethylene glycol dinitrate (EGDN) and nitroglycerine (NG) presumed to occur from storage with dynamites in commerical blasting company magazines. Other trace components are presumed to arise from the manufacturing process.

ISSN:0737-0652    

DOI:10.1080/07370658608011355

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor