Determining the Potential of Radiofrequency Resonance Absorption Detection of Explosives Hidden in Airline Baggage

The potential of the radiofrequency resonance absorption spectroscopy (RRAS) techniques for detecting specified quantities of specific explosives in checked airline luggage was investigated. The RRAS techniques considered in this study included nuclear magnetic resonance (NMR), electron spin resonance (ESR) and nuclear quadrupole resonance (NQR). It was found that all the explosives, except black powder, could be detected by NMR and that the NMR response from explosives could be separated from the response produced by other materials likely to be found in luggage. It was also found that black powder and smokeless powders could be detected by ESR but none of the other explosives produced an ESR response. NQR was found useful only for the detection of the RDX base explosive C-4 but even this material could be more sensitively detected by NMR. The results were sufficient to demonstrate the basic feasibility of using NMR for detection of responses from materials in the large volumes required to inspect checked baggage, but limitations on the available laboratory equipment prevented positive detection of explosives or explosives simulants in this space.