Remote Spectrometry and detection of organic and explosive materials through the generation of DC plasma

Remote spectroscopy of material plasmas can be used well to detect and identify the material identity especially the explosive and organic materials. The plasma can be generated either through the applying high power density laser radiations or high DC voltages in the vacuum circumstance. In this paper, to generate the material plasmas, a high DC voltage of 2 kV was applied in the T-shaped lamp with argon atmosphere. The plasmas of two explosive materials of TNT and picric acid and two organic materials of 4-nitrobenzoic acid and 3,5-dinitrobenzoic acid in quantities of 35 mg were at first generated and then their spectra were measured from distances of 1.55, 2, and 2.31 meters. The spectra of material plasmas ranged from 200 nm to 800 nm consisting of lines C2, H, O, N, and Ar. The limit-of-detection from a distance of 2 m was determined consequently. Finally, with the use of two methods, the explosive materials were distinguished from the organic ones and the calibration curve was also prepared.