Effect of Photoemission on Operating Voltage in the High-Voltage Hollow Cathode Discharge

Abstract

Photoelectric effect on the operating voltage of hollow cathode discharge was investigated using an insulator tube inserted into the hollow cylindrical Cu cathode. Discharge gas was He. Materials of the tube used were quartz and MgF₂. Copper-coated tubes of these materials were also used. The coating was carried out by cathode sputtering in the hollow cathode discharge tube. The operating voltages of discharge for the coated tubes were much higher than those for the quartz and MgF₂ tubes. The Cu-coated tubes did not transmit ultraviolet light giving rise to a photoelectric effect. It has been concluded that the reduction of photoelectric effect is one of the causes leading to the high operating voltage of hollow cathode discharge.