| 摘要 |
PURPOSE:To effectively start arc discharge by a hollow cathode discharger, simplify its chamber structure, and make a hollow cathode inside the discharge chamber by irradiating light to the hollow cathode inside the discharge chamber and heating it with a light emitter provided outside the discharge chamber. CONSTITUTION:An optical transmission window 22 is provided on a part of the external surface of a discharge chamber 21 which is kept under a low pressure. For example, a cylindrical hollow cathode 1 consisting of tantalum and an anode 2 which faces the cathode 1 in the axial direction of this cathode are arranged. On the other hand, for example, a light emitter 23 consisting of an infrared lamp or the like is provided outside the discharge chamber 21 opposing to the optical transmission window 22. The infrared radiation generated by this light emitter 23 is concentrated by a condenser lens 24 and is irradiated on the side end of the anode 2 in the hollow cathode 1 through the optical transmission window 22. This can effectively start arc discharge between the hollow cathode and anode, simplify the structure inside the discharge room, and prolong the life span of the cathode. |
