| 摘要 |
PURPOSE:To enable stable discharge at a hollow section of a hollow cathode and to realize long device life by coating an outer surface of the hollow cathode with an electric insulating material which resists ion impulse. CONSTITUTION:A hollow cathode 3 is positioned in the same axis of a laser tube 1 and nickel or nickel alloy such as inconel is used. A circumference of the hollow cathode 3 is coated with an electric insulating material 14 which resists ion impulse, and an insulating film is formed by flame-spraying alumina ceramics, etc., about 100mum in thickness. Such alumina ceramics is highly heat- resistant and insulating and gas emission at a high vacuum is little. Coating of the circumference of the hollow cathode with the electric insulating material 14 in this way can reduce generation of spatter product at glow discharge. Device life can be thereby greatly improved. |
