Control of charge-up on insulating glass in vacuum due to plasma processing

In order to control charge-up on insulating glasses used for high-voltage vacuum equipment, H₂ plasma processing on the glass surface was studied. Borosilicate glass plates were used as test samples. The glasses were exposed to H₂ plasma produced by AC (60 Hz) voltage application. The surface resistivity of the glass was deceased with H₂ plasma processing time. By H₂ plasma exposure for 20 minutes, the surface resistivity was reduced from 10¹⁷ Ω to 10¹² Ω. Due to the reduction of the surface resistivity, charge-up of the glass irradiated by electron beam can be controlled to the level not to cause surface flashover