Collision-induced microwave absorption in Ne–Xe and Ar–Xe gaseous mixtures at 2.3 cm−1

Collision-induced microwave absorption has been observed at 2.3 cm−1 for the inert gas mixtures Ne–Xe and Ar–Xe. The absorption coefficient has been measured at room temperature for a range of density products up to 15 000 amagat2 for different density ratios. The present results are compared with the results obtained earlier at 4.4 cm−1. The intracollisional absorption coefficient arising from two body interactions is approximately proportional to the square of the frequency for both mixtures. The intercollisional interference effects have led to a larger suppression of the absorption than was observed previously at 4.4 cm−1. An expression for the intercollisional line shape factor was used to fit the data. At high densities, there is observed a marked increase in the absorption which has also been observed at 4.4 cm−1 and which may be attributed to many body collisions.