Portable Lidar for Atmospheric Monitoring of Toxic Chemicals

In Phase II we will develop a portable differential absorption lidar (DIAL) for remote measurement of toxic carcenogenic chemicals, such as, benzene, benzo(a)pyrene, formaldehyde, TCDD, released during the open-burn or detonation of hazardous propellents,munitions and pyrotechnics. The key component of this lidar is a compact all-solid-state laser developed by us, which is rapidly tunable in the mid-IR (2.7-4¿m). Phase I simulations have shown that 150ppb range resolved and 30ppb path integrated (for1.5km) measurements of benzene are obtained for a few seconds of averaging with a lidar equipped with a 8"diameter telescope, 100Hz, 1mJ/pulse laser tunable in 3-4¿m region. Atmospheric lidar absorption measurements of methane were also performed in PhaseI with a tunable mid-IR DIAL system and showed good agreement with directly measured methane concentrations. A prototype mid-IR chemical DIAL will be built in Phase II and tested using non-toxic simulants. As option tasks the self-powered lidar system willbe made robust for field operation by using a modular transmitter/receiver unit that is fiber coupled to laser/power supply unit. A software program will be developed for autonomous lidar operation to provide rapid concentration measurements during OB/ODevents. The lidar will be delivered to EAFB.