Linewidth measurements of the ν2 + ν4 R(29) absorption in CF4

Linewidth measurements of the ν₂ + ν₄ R⁺(29) A₁⁴ + E⁹ + F₁¹⁴ absorption at 1073.279 cm⁻¹ were made in the pressure range of 0.5 to 50 Torr CF₄. The data, after correction for Doppler broadening, reduce to a self-broadening coefficient of 10.8 ± 0.4 MHz/Torr. Comparisons of the linewidth for pure CF₄ with the linewidth of an Ar-CF₄ mixture and with the prediction of the hard-sphere, gas-kinetic model imply a relaxation mechanism that is not dominated by a resonant (V-V) process, and has an effective cross section that is intermediate in size between the cross sections associated with dipole-dipole and hard-sphere collisions.