Electron detachment for 50 keV He-ions leading to metastable and ground-state atoms

Abstract
The ratio of the cross sections for single-electron detachment leading to metastable and ground-state atoms for 50 keV He- ions in H2 has been measured. Up to 58% of the resulting neutral He atoms are shown to be in one of the two metastable excited states. It is argued that mainly the 23S state is populated.