A Laser-based Explosives Sensor
نویسنده
چکیده
Trace explosives residues of CL20 (hexanitrohexazaisowurtzitane) and RDX (hexahydro-1,3,5-hexanitro-1,3,5-triazine are measured in real-time by surface laser photofragmentation-fragment detection (SPFFD) spectroscopy at ambient conditions. A 248nm laser photofragments the target residue on a substrate, and a 226-nm laser ionizes the resulting NO fragment by resonance-enhanced multiphoton ionization by means of its A-X (0,0) transitions near 226 nm. We investigate the effects of laser wavelength and energy, delay between photofragmentation and ionization lasers, and residue concentration on signal intensity. A signal-to-noise analysis yields a limit of detection of 7.1 ng/cm for CL20 and 1.4 ng/cm for RDX at 1atm and 298K.
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