Line-mixing effects in the 3v3 band of CO2 perturbed by Ar

摘要: Measurements of absorption coefficients in the 3v3 band CO2 at 1.44 μm perturbed by Ar up to 146 bar have been analyzed using two line-mixing theoretical calculations within impact approximation. In first approach, relaxation operator is treated semi-classically with adiabatic corrections. second, modelled Energy Corrected Sudden (ECS) approximation associated a power fitting law providing basic rotational state-to-state rates. Although line-coupling spectroscopic cross-sections models are significantly different, they both lead satisfactory agreement bandshapes moderate densities (< 100 Amagat). Significant deviations between experimental and calculated spectra appear higher densities. They mainly attributed probable breakdown binary collision approximations number reasons including an incorrect ECS calculation interbranch coupling, nonlinear density dependence due finite volume molecules, neglect unknown imaginary part off-diagonal elements matrix.