| 摘要 |
PURPOSE: To prevent acceleration of deterioration of a laser tube, by avoiding impropriety that a gas pressure is detected high by mistake. CONSTITUTION: In a discharging part 9, electrodes (an anode 4 and a cathode 5) for arc discharge which discharge and excite argon gas, a thin tube 6 for arc discharge, and a pair of electrodes 18 for glow discharge are arranged in a laser tube 1. A grow discharge voltage is measured with a measuring circuit 16. When the measured value reaches a voltage which corresponds to the lowest gas pressure necessary for normal laser oscillation, a gas supply circuit 15 supplies gas in a gas reservoir 10 to the laser tube 1 by outputting a gas supply signal and temporarily releasing a solenoid valve 11. |
