Spectra calculations in central and wing regions of CO2 IR bands between 10 and 20 μm. I: model and laboratory measurements

摘要: Abstract Temperature (200– 300 K ) and pressure (70– 200 atm dependent laboratory measurements of infrared transmission by CO2–N2 mixtures have been made. From these experiments the absorption coefficient is reconstructed, over a range several orders magnitude, between 600 1000 cm −1 . The elevated densities used in (up to magnify contribution wings ν2 band lines. In order analyze spectra, theoretical model based on energy corrected sudden approximation proposed which accounts for line-mixing effects within impact approximation. This approach uses associated parameters built previously Q branches (JQSRT 1999;61:153) but extends it now including all P, Q, R No adjustable are fundamental properties collisional relaxation operator verified using renormalization procedure. Comparisons measured calculated spectra confirm that neglecting (Lorentzian model) leads an overestimation up three magnitude far wings. On other hand, satisfactory results both regions dominated contributions local lines wing: correctly modeled where varies more than four magnitude. largest discrepancies, appear about 150 from center, can be due finite duration collisions or uncertainties experimental determination very weak absorption.