ANALYSIS OF O-2-BROADENING OF (CH3F)-C-12 LINES IN THE 6.8-MU-M SPECTRAL REGION

Using a tunable diode-laser spectrometer, we have measured the O-2-bro adening coefficients for 45 lines of methyl fluoride in the P-Q and R- Q branches of the upsilon(2) parallel band, and in the P-P, (P)Q, R-P, P-R, (R)Q and R-R branches of the upsilon(5) perpendicular band. Thes e lines with J values ranging from 1 to 23 and K from 0 to 9 (K less t han or equal to J) are located in the spectral range 1416-1573 cm(-1). The collisional halfwidths are obtained by modeling each spectral lin e with a Voigt and a Rautian profile. The noncorrelated Rautian model leads to larger values of broadening coefficients than the Voigt model . These coefficients have also been calculated from a semiclassical mo del in which the intermolecular potential includes electrostatic, indu ction, and dispersion energy contributions. The results in the P, Q, a nd R branches of the upsilon(2) and upsilon(5) bands are in overall ag reement with the experimental data. (C) 1998 Academic Press.