			15min:

COLLISION-INDUCED ABSORPTION IN PURE O₂, CO₂, AND N₂.

Y. I. BARANOV, W. J. LAFFERTY AND G. T. FRASER, Optical Technology Division, NIST, Gaithersburg, MD 20899.

Collision-induced absorption (CIA) of the fundamental band of pure oxygen has been obtained over the temperature range -80^o to +85^oC. The integrated band intensity is at a minimum at 0^oC and increases on either side of this temperature. Band intensities of the CIA in the fundamental band of N₂ as well as the CO₂ Fermi dyad are currently under investigation. Preliminary results indicate that the temperature dependence of the band intensity of the nitrogen CIA parallels that of O₂. In contrast, the integrated intensities of the 10⁰0/02⁰0 Fermi dyad in CO₂ increase steadily as the temperature is decreased. The integrated intensities double as the temperature goes from +72^o to -80^o C. This indicates that at low temperatures the bound dimer is the major species in the gas. The band structure obtained at elevated temperatures will be presented.