Influence of energy transfer processes on the rovibrational characteristics of CO2 in low-temperature conversion plasma with Ar and He admixture.

The influence of argon and helium on the rovibrational kinetics of carbon dioxide (CO2) and CO in low-temperature conversion plasma is investigated. With this objective, a combined experimental and computational study is conducted, applying quantum cascade laser infrared absorption spectroscopy to a pulsed DC CO2 glow discharge with varying noble gas admixture and modeling it with a two-term Boltzmann solver. Time-resolved rovibrational temperatures and dissociation fractions are presented, exhibiting an increase in rotational-vibrational non-equilibrium and an increasing CO2 conversion with argon (Ar) and helium (He) admixtures.

Crosstalk-Free Excitation Scheme for Quantitative OH Laser-Induced Fluorescence in Environments Containing Excited CO.

Spectral overlap in the single-photon laser-induced fluorescence between the 3064 Å system of OH and the third positive system of CO is detected in a highly-excited environment, namely, a CO-HO plasma. The overlap is distorting excitation and fluorescence spectra as well as fluorescence time decays of commonly used excitation transitions of OH. As a consequence, systematic errors are introduced into the determination of temperatures, gas compositions, and absolute number densities.