Trace detection of nitrogen-based explosives with UV-PLF

Trace detection of energetic materials is a method to screen personnel, packages and other items for concealed explosives. It is likely, that a person who carries explosives will contaminate himself and the package with the explosive. We present first results on the development of a compact detector combining Pulsed Laser Fragmentation (PLF) with fragments detection. A passively q-switched UV microchip laser photofragments surface contaminations. The concentration ratio of the fragments NO and NO2 is a sufficient indicator for the presence of nitrogen-based explosives. For TNT, the results suggest, that a surface density as small as a few ng/cm2 can be reliably detected.