Experimental Limits on the Translational Absorption in Inert Gas Mixtures near 1 cm−1

The experimental method and results of an attempt to make a direct measurement of the pressure-induced translational absorption are described. Measurements were made on He–A and Ne–A mixtures at pressures up to 2500 p.s.i.g. at a frequency of about 33 GHz (1 cm−1). The results establish an upper limit to the values of the absorption coefficients in this frequency region. The values are consistent with the values calculated from theory and infrared measurements if the anti-correlated collision approximation is used.