| 摘要 |
PURPOSE:To detect accurately a discharge current even in the form of a pulse, by receiving a discharge light generated in a discharge tube wherein gas laser medium is sealed and is exited by discharging, and detecting from the light quantity an electric signal converted in accordance with the discharge current value in the discharge tube. CONSTITUTION:In the vicinity of the outer wall of a discharge tube where a positive column is generated, ale arranged light receiving equipments 26 and 27 of fiber as the transmission guide of discharge light which receives the dischare light of a glow discharge and guides it outward. Optical fibers 28 and 29 are connected to photo-detectors 30 and 31 composed of silicon photodiode as a conversion element arranged in a high voltage power source 21, and, by these photodetectors 30 and 31, the discharge light is converted into an electric signal in accordance with the light quantity. Current indication parts 32 and 33 receive the electric signals from the respective photo-detectors 30 and 31 thereby obtaining discharge current values and indicate them. |
