COLLISION-INDUCED ABSORPTION IN PURE $O_{2}, CO_{2}$, AND $N_{2}$

Abstract

Collision-induced absorption (CIA) of the fundamental band of pure oxygen has been obtained over the temperature range $-80^{\circ}$ to $+85^{\circ} C$. The integrated band intensity is at a minimum at $0^{\circ} C$ and increases on either side of this temperature. Band intensities of the CIA in the fundamental band of $N_{2}$ as well as the $CO_{2}$ Fermi dyad are currently under investigation. Preliminary results indicate that the temperature dependence of the band intensity of the nitrogen CIA parallels that of $O_{2}$. In contrast, the integrated intensities of the $10^{0}0/02^{0}0$ Fermi dyad in $CO_{2}$ increase steadily as the temperature is decreased. The integrated intensities double as the temperature goes from $+72^{\circ}$ to $-80^{\circ} C$. 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.