Detection of explosives at trace levels by Laser Induced Breakdown Spectroscopy (LIBS)

摘要

In order to realize a compact instrument for detection of explosive at trace levels, LIBS was applied on residues from different explosives and potentially interfering materials. The residues were simply placed on aluminum support and the measurements were performed in air. Spectral line intensities from the characteristic atoms/molecules and their ratios, are strongly varying from one sampling point to another. The reasons for such variations were studied and explained, allowing establishing a suitable procedure for material recognition. Correct classification was always obtained for five types of explosives, while for TATP, nitroglycerine, DNT and EGDN this occurred only for very thin residues. In all the cases, the estimated detection threshold is between 0.1 ng and 1 ng.