Stand-off detection of chemicals by UV Raman spectroscopy
- Department of Advanced Technology, Brookhaven National Laboratory, Upton, New York 11973 (United States)
Experimental results are reported on a mobile, stand-alone, solar-blind ultraviolet (UV) Raman lidar system for the stand-off detection and identification of liquid and solid targets at ranges of hundreds of meters. The lidar is a coaxial system capable of performing range-resolved measurements of gases and aerosols, as well as solids and liquids. The transmitter is a flash lamp pumped 30 Hz Nd:YAG laser with quadrupled output at 266 nm. The receiver subsystem is comprised of a 40 cm Cassegrain telescope, a holographic UV edge filter for suppressing the elastic channel, a 0.46 m Czerny-Turner spectrometer, and a time gated intensified charge-coupled device (CCD) detector. The rejection of elastic light scattering by the edge filter is better than one part in 10{sup 5}, while the transmittance 500 cm-1 to the red of the laser line is greater than 50%. Raman data are shown for selected solids, neat liquids, and mixtures down to the level of 1% volume ratio. On the basis of the strength of the Raman returns, a stand-off detection limit of {approx}500 g/m2 for liquid spills of common solvents at the range of one half of a kilometer is possible. (c) 2000 Society for Applied Spectroscopy.
- OSTI ID:
- 20217411
- Journal Information:
- Applied Spectroscopy, Journal Name: Applied Spectroscopy Journal Issue: 6 Vol. 54; ISSN 0003-7028; ISSN APSPA4
- Country of Publication:
- United States
- Language:
- English
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