Double-pulse laser fragmentation/laser-induced fluorescence of surface traces of nitrocompounds
S.M. Bobrovnikov1,2, E.V. Gorlov1,2, V.I. Zharkov1, S.N. Murashko1,2
1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
2National Research Tomsk State University, Tomsk, Russia
Keywords: nitrocompound, laser fragmentation, nitric oxide, NO fragment, laser-induced fluorescence
Abstract
Ensuring security against threats associated with the use of explosive devices requires the development of effective methods for remote detection of explosive traces on different surfaces. This work discusses the way of improving the efficiency of the laser fragmentation/laser-induced fluorescence (LF/LIF) method for remote detection of surface traces of nitrocompounds. Using trinitrotoluene (TNT) as an example, it experimentally shows that time separation of fragmenting and probing pulses can significantly increase the efficiency of LF/LIF compared to single-pulse and simultaneous two-pulse irradiation. The relative intensity of fluorescence of NO fragments of TNT traces is assessed versus the fluence of fragmenting Nd:YAG laser (266.038 nm) and probing KrF laser (247.866 nm) at an optimal interpulse delay of 200 ns. The results can be used to improve the sensitivity and/or range of detection of nitrocompound traces by the LF/LIF method.
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