Absolute number density measurements of hydroperoxyl radical in a nanosecond pulse discharge using cavity ring-down spectroscopy

Frederickson, Kraig

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https://hdl.handle.net/2142/100527 Copy

Description

Title

Absolute number density measurements of hydroperoxyl radical in a nanosecond pulse discharge using cavity ring-down spectroscopy

Author(s)

Frederickson, Kraig

Contributor(s)

• Adamovich, Igor V.
• Miller, Terry A.

Issue Date

2018-06-21

Keyword(s)

Spectroscopy as an analytical tool

Abstract

A recently implemented cavity ring-down spectrometer has been used to perform absolute number density measurements of hydroperoxyl radical (HO2) generated in a repetitive nanosecond-duration, pulse discharge sustained in a mixture of H2/O2/Ar. The probe source for the spectrometer is a custom-built, injection-seeded, optical parametric oscillator emitting an idler beam in the 1500 nm region accessing the first overtone (2ν1) of the O-H stretch. Water vapor was used as a standard species to characterize the spectrometer and provide estimates of the spectral linewidth, sensitivity, and noise level. A specially constructed ring-down cell, with the central portion consisting of rectangular quartz channel tubing and a pair of copper plate electrodes, was used to produce a repetitively pulsed discharge in a H2/O2/Ar mixture. Narrow bandwidth cavity ring down spectra are acquired of a hydroperoxyl absorption feature composed of numerous closely spaced ro-vibrational lines centered at 6638.20 cm−1 and number density is determined from the resulting spectral line. This is believed to be the first detection and quantitative measurement of hydroperoxyl radical produced in a nanosecond pulse discharge. The measured number density is compared to the value predicted by the kinetic model of a nanosecond pulse discharge in a reacting H2/O2/Ar mixture.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100527

DOI

10.15278/isms.2018.RH02

Copyright and License Information

Copyright 2018 Kraig Frederickson

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