EFFECT OF HIGH PRESSURES ON THE INFRARED AND RED ATMOSPHERIC ABSORPTION BAND SYSTEMS OF OXYGEN

Abstract

Absorption intensities in the 0–0 and 1–0 bands of the infrared [Formula: see text] and the 0–0 band of the red [Formula: see text] band systems of oxygen were measured in the pure gas in the range 50 to 150 atm and in O2–N2, O2–A, and O2–He mixtures up to 3000 atm total pressure at 25 °C. The integrated absorption coefficient of each band is expressed as a power series in ρO2 and ρf, the Amagat densities of oxygen and the foreign gas, respectively. The coefficient of the linear term AρO2 is a measure of the intrinsic (magnetic dipole) absorption of the O2 molecule; it is much greater in the red than in the infrared system. The quadratic term, BρO22, gives the induced absorption in O2–O2 pairs; B is about ten times greater in the infrared than in the red system. These results explain intensity anomalies which have been observed in condensed oxygen. Induction effects in O2–N2 and O2–A pairs are much smaller than in O2–O2 pairs, and scarcely observable in O2–He pairs. The significance of these results is discussed.