AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Raman Spectroscopy of Aerosol and Vapor Chemical Warfare Agents
ERIK EMMONS, Francis D'Amico, Gary Kilper, Steven Christesen, Aime Goad, David Sickenberger, Jeys Thomas, Roshan Aggarwal, Mitesh Amin, Michelle Clark, Lewis Farrar, Bradford Perkins, U.S. Army Edgewood Chemical Biological Center
Abstract Number: 313 Working Group: Single Aerosol Particle Studies - Techniques and Instrumentation
Abstract We have developed a Raman spectroscopy system for detecting vapor and aerosolized chemical warfare agents for the purpose of providing warning of potential attacks. The instrument is capable of single or few aerosol particle detection under favorable conditions. A high-power 10 W 532 nm laser is used to excite Raman scattering from a vapor or aerosol jet that it crosses at 90 degrees. A high-efficiency spectrometer system is then used to detect the scattered light. Two lenses are used to collect the scattered light emitted towards and away from the spectrometer entrance slit, and all the Raman scattered light is directed to the entrance slit. In addition, an inertial concentrator is used to increase the detection efficiency of aerosolized samples, and an optional photobleaching cell can be used to reduce material fluorescence. Tests with live chemical agents have shown the ability to detect and identify threat materials such as GB (sarin) and VX nerve agents in both vapor and aerosol form in real time. Measurements of simulants and agents will be presented. In additional, morphology dependent resonance has been observed for some highly fluorescent aerosol particles where only one or a few particles are being measured at a time. The instrument may have additional applications in basic research, environmental monitoring, and atmospheric science.