Metastability-exchange and depolarising collisions in xenon and krypton

Abstract
Collisions between rare-gas atoms in the 3P2 metastable state and in the ground state were studied. The metastable atoms were created by a discharge and oriented by optical pumping, and pressure broadening of their magnetic-resonance curves was measured. For xenon, mixtures of even and odd isotopes were used, leading to a determination of the cross section for metastability-exchange collisions. For krypton the results are reported for the disorientation of the metastable state in the natural gas. In addition the disorientation cross section has been measured of the krypton metastable state through collisions with helium.