Electron Impact Desorption under 2 and 3 keV Electron Beam Conditions

Abstract

To simulate electrical breakdown phenomena occuring on an anode in vacuum gap, energies and mass species of ions emitted from target electrodes bombarded by 2 and 3 keV electron beams are measured. Target materials used were Al, Cu and Fe. Ions emitted had their kinetic energies of several eV, which coincides with results obtained from dc vacuum prebreakdown measurements. Dominant mass species of emitted ions are H⁺ and H₂⁺, and sometimes H₂O⁺, O⁺. From these results it is pointed out that electron impact desorption on an anode of a vacuum gap is one of the most important phenomena which govern electrical breakdown in the gap.