Charge Changing Processes for Helium Beam Involving Metastable Atoms in Molecular Hydrogen

The cross section for one-electron stripping from the ground state and metastable helium atoms in molecular hydrogen gas have been measured in the energy range from 14 to 50 keV using the beam attenuation technique developed by Gilbody et al. The fraction of the metastable atoms in the neutral helium beam after traversing a thin hydrogen gas has also been determined, from which the cross sections for one-electron capture by singly charged helium ions resulting in the ground state and metastable helium atoms have been estimated. The present results are in good agreement with previous experimental data and calculations by Bates et al.