Collisional Broadening of Vibrational-Rotational CO2 Lines by Buffer Gases

Unsaturated absorption coefficients in pure CO 2 and binary mixtures of CO 2 with buffer gases M j (He, Ar, Kr, Xe, N 2 , O 2 , CO, N 2 O, 13 C 16 O 2 ) were measured with a tunable CO 2 laser at the central frequencies of the R (8), R (22), R (34), P (8), P (22), and P (36) CO 2 spectral lines of the 10 0 0–00 0 1 transition at a temperature of 300–700 K. A technique is described and the coefficients of self-broadening and broadening of CO 2 spectral lines by a buffer gas M j are calculated. It is shown that the efficiency of the CO 2 interaction with diatomic and triatomic molecules is determined by the electric moment; in the case of inert gases, the mass factor plays the major role. It is ascertained that the temperature dependences of the collisional broadening of CO 2 spectral lines can be highly accurately approximated by power functions with two different exponents.