Observation of Ion Motion in Hydrogen Stark Profiles

Abstract
We have measured the central part of the Balmer Hβ or Dβ line in similar stabilized arc plasmas, but of different chemical compositions. We have found an ion-motion effect which appears to scale with the inverse square root of the reduced mass of the radiator-perturber system and which, for Hβ at least, essentially removes one of the largest remaining discrepancies between experiment and Stark-broadening theory.