Time-resolved wavelength modulation spectroscopy measurements of HO{sub 2} kinetics

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Applied Optics

DOI:https://doi.org/10.1364/AO.36.005817· OSTI ID:365346

High-frequency wavelength modulation spectroscopy (WMS) has been applied to the detection of the hydroperoxyl radical (HO{sub 2}) in a laser photolysis and long-path absorption pump-probe kinetics reactor with a near-infrared distributed feedback diode laser. The HO{sub 2} is formed by the 355-nm photolysis of Cl{sub 2} in the presence of CH{sub 3}OH and O{sub 2} and monitored by a phase-sensitive detection of the second-harmonic (2f) signal in the 2{nu}{sub 1} band with a 1.5-{mu}m diode laser directly modulated at 5 MHz. The measured 2f WMS signal is calibrated by direct absorption and converted to an absolute number density with the known absorption line strength of the HO{sub 2} line at 6625.80 cm{sup {minus}1}. The utility of time-resolved WMS as a second-order kinetics probe is demonstrated through the measurement of the HO{sub 2} self-reaction rate constant at 295 K. {copyright} 1997 Optical Society of America

• OSTI ID: 365346
• Journal Information: Applied Optics, Journal Name: Applied Optics Journal Issue: 24 Vol. 36; ISSN APOPAI; ISSN 0003-6935
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
CHEMICAL ANALYSIS
CHLORINE
CONCENTRATION RATIO
HYDROGEN COMPOUNDS
INFRARED SPECTRA
LASER SPECTROSCOPY
METHANOL
OXYGEN
OXYGEN COMPOUNDS
PHOTOLYSIS