Metastable He⁺(2S) production by a RF ion source

Abstract

3He+(2S) production by a RF ion source has been measured by detecting the 30.4 nm radiation emitted when the 2S state is quenched in a high electric field. The production was maximum when extraction voltages and gas pressures in the source were low. The highest fraction He+(2S)/He+(1S) observed was 0.08%. This fraction is estimated to be accurate to within a factor of two.