Line strengths, self-broadening, and line mixing in the 20(0)0 <- 01(1)0 (Sigma <-Pi) Q branch of carbon dioxide

Using a difference frequency spectrometer we have measured the Q(2) to Q(38 ) 20(0)0 <-- 01(1)0,Sigma <--Pi transitions of carbon dioxide at 296 K and pressures up to 15 kPa. These low pressure spectra were analyzed using both the Voigt model, and an empirical line shape that blends together a hard c ollision model and a speed dependent Lorentzian profile. The broadening coe fficients were obtained with an accuracy of 1% or better. The low density o r first order low pressure line mixing parameters were also determined. We have compared both our measured low pressure line-mixing parameters and the complete band spectrum at high pressures with those predicted by a relaxat ion matrix calculated from an EPG fitting law. Spectra at the highest press ures were recorded using both the difference frequency spectrometer and an FTIR spectrometer, the temperature for the latter experiments being 303 K. The vibrational band intensity and linear pressure shift of the branch as a whole were also measured. (C) 2000 American Institute of Physics. [S0021-9 606(00)01519-1].