MEASUREMENT OF VIBRATIONAL LINE-PROFILES IN H(2) RARE-GAS MIXTURES - DETERMINATION OF THE SPEED DEPENDENCE OF THE LINE SHIFT

High-resolution inverse Raman experiments for H-2 diluted in Ar have r evealed unusual Q-line profile features at various concentrations whic h have been interpreted in terms of speed-changing collisions. A more general approach including both speed- and phase-changing collisions h as led to an alternative interpretation of these features. In order to further analyze the role of these various collisional mechanisms, new experiments have been performed. Pure H-2 and H-2 perturbed by Ne, Ar , and Xe have been investigated at various temperatures between 295 an d 800 K.