Explosives detection by LI-MS and resonance Raman spectroscopy

This report summarises the experimental development and results from the second year of the FOI strategic project on explosives detection. Experimental work has been focused on two areas. One is the ESSEX (Extremely Sensitive and Selective Explosive Detector), a trace detection system based on laser ionisation mass spectroscopy (LI-MS). The experimental results on toluene and chlorobenzene are shown to demonstrate the applicability of the technique. The second is a stand-off system based on Raman spectroscopy. Initial experiments on e.g. the liquid "explosive" nitromethane demonstrate the possibility to obtain identification spectra from 12 meters distance at a detection time of 1 second. Also included are short theoretical descriptions for these techniques.