ABSTRACT Two Photon Laser Induced Fluorescence (TALIF) is used to measure absolute
oxygen atom concentrations as a function of time in O2/He, O2/N2, and methane/air plasmas
produced with a 20 nanosecond duration, 20 kV pulsed discharge. While the pulser is
capable of repetition rates as high as 50 kHz, the data reported here was purposefully
obtained at much lower repetition rate, 10 Hz, in order to limit the number of pulses
experienced by the flowing, room temperature gas sample during its resonance time within …

Abstract Two Photon Laser Induced Fluorescence (TALIF) is used to measure time-
dependent absolute oxygen atom concentrations in O 2/He, O 2/N 2, and CH 4/air plasmas
produced with a 20 nanosecond duration, 20 kV pulsed discharge at 10 Hz repetition rate.
Xenon calibrated spectra show that a single discharge pulse creates initial oxygen
dissociation fraction of∼ 0.0005 for air like mixtures at 40-60 torr total pressure. Peak O
atom concentration is a factor of approximately two lower in fuel lean (φ= 0.5) methane/air …