SF6 GAS INTEGRATED-INTENSITIES AS A FUNCTION OF DENSITY

Index of refraction measurements on SF6 at microwave and visible frequencies suggest that there are contributions from infrared (i.r.) collision-induced absorption (CIA) bands, as well as the i.r.-allowed bands. Thus far, absorption measurements of pure CIA bands cannot account for all CIA contributions to the index of refraction. This discrepancy indicates important CIA contributions must also occur within i.r. active bands. However, the CIA contribution has proved difficult to measure. Measurements at low-density of vibrational band integrated intensities have now been made, in addition to the previous measurements at high densities, and the existence of CIA bands is pointed out within the i.r. active 3-nu-3 band.