Study of velocity-changing collisions in excited Kr using saturation spectroscopy

A saturated-absorption experiment is used to measure the effects of velocity-changing collisions between Kr* metastable atoms ($4p^{5}5s{\left[\frac{3}{2}\right]}_2$) and He and Ar perturbers. Comparison between experimental profiles and profiles calculated assuming hard-sphere collisions between Kr* and perturber atoms confirms the calculations of Borenstein and Lamb concerning the change of velocity associated with a collision. Furthermore it is found that the rate of velocity-changing collisions is consistent with the predictions of kinetic theory.