9
Ultrasensitive
Detection of Aerosol
Dr. Angus J.
Henderson,
Dr. Dennis D.
Lowenthal, Business Official, dennis.lowenthal@aculight.com
DOE Grant No.
DE-FG02-05ER84267
Amount: $99,997
The
Department of Energy requires improved measurement techniques to quantify trace
gas species in the atmosphere, in order to achieve further understanding of the
formation of aerosols and their role in climate change. This project will combine a novel,
ultra-sensitive, photo-acoustic detection technique with a high power, widely
tunable mid-infrared laser source to enable rapid, sub-part-per-billion
detection of a wide range of species including aerosol precursors such as
ammonia and nitric acid. Key advantages
of the technique are the ability to measure multiple gas species, the small
size of the detector unit, and the absence of any requirement for cryogenic
cooling in the system. In Phase I, a
mid-infrared optical parametric oscillator (OPO) with an output power of 1 Watt
will be developed as the excitation source for quartz-enhanced photo-acoustic
spectroscopic (QEPAS) detection of multiple trace gas species. Direct absorption spectra of a variety of
species will be acquired, and real-time concentration measurements of a
calibrated trace gas sample will be performed using the QEPAS technique. Finally, an assessment of the technique in
terms of its ultimate sensitivity and range of species detectable will be made,
leading to a design for a Phase II multi-species detection system.
Commercial Applications and Other Benefits as described by the awardee: The new system should provide a detection capability for wide variety of species with high sensitivity and should contribute to a wide range of industrial and scientific problems, including detection of impurities in gases used in semiconductor fabrication, measurement of hydrocarbon gas leaks in the petrochemical industry, studies of pollution sources and of aerosol formation for investigation of climate change.