$N_{2}$ BROADENING OF $CO_{2}$ MEASURED AT LOW TEMPERATURES

Abstract

The absorption coefficients of $N_{2}$-broadened $CO_{2}$ lines were obtained from intensity measurements of the $\nu_{1} + 4\nu_{2} + \nu_{3}$ and $2\nu_{1} + 2\nu_{2} + \nu_{3}$ bands at 6228 and $6348 cm^{-1}$ respectively. A cooled absorption ceil with a base path of 0.75 m was used together with a Michelson interferometer. Theoretical resolution was $0.125 cm^{-1}$. Spectra were recorded at 193, 213, 233, and 293$^\circ K$ with total pressures of 5 to 200 Torr. Broadening gas pressure varied between 5 and 100 Torr. A path length of 33 m was used in all cases. These determinations at low temperatures are of interest in the study of the Martian atmosphere.