Quantum Theory of CollisionInduced Absorption in RareGas Mixtures
Abstract
A theoretical calculation of the collisioninduced farinfrared absorption, which has been observed in raregas mixtures, is carried out using the quantummechanical expression for the absorption coefficient. Using a simple empirical form to describe the variation of the collisioninduced dipole moment with internuclear separation, and using planewave eigenstates (i.e., assuming straightline collision paths), an analytic expression is obtained for the spectrum which agrees well with the experiments. Comparison with a previous classical calculation based upon the same model shows that quantum effects are small at room temperature except in the highfrequency wing of the spectrum. A number of analytic integrations allow us to derive simple expressions for the correlation function, relaxation time, static dielectric constant, and other spectral invariants.
 Publication:

Physical Review
 Pub Date:
 August 1967
 DOI:
 10.1103/PhysRev.160.159
 Bibcode:
 1967PhRv..160..159L