Infrared emission spectroscopy of CO_2 at high temperature. Part I: Experimental setup and source characterization

摘要

An experimental setup is developed to analyze infrared emission of CO_2 plasmas at atmospheric pressure and temperatures up to 5000K. A microwave discharge is used to produce the hot gas mixture and emission is recorded by a Fourier transform spectrometer with a spectral resolution between 0.01 and 0.1cm~(-1). The plasma is confined inside quartz or sapphire tubes which perturb the measurements through refraction, reflection, absorption and emission. We present in this part the experimental setup, an analysis of tube effects, and the characterization of the plasma in terms of temperature and molar fraction distributions using CO emission in the overtone vibrational bands Δv=2. Analysis of the measurements of CO_2 emission in the 2.7μm and 4.3μm regions, and comparisons with calculations using different spectroscopic databases are given in the companion paper (Depraz et al., in press) [1].