| 摘要 |
PURPOSE:To prevent abnormal discharge from occurring without reducing the effect of a ballast capacitor by reducing the thickness of the lower part of a discharge tube of a gas laser apparatus thinner than that of the upper part. CONSTITUTION:The thickness of the lower part 1b of a discharge tube 1 is thinner than that of the upper part 1a. Laser medium gas exists in the tube 1, a discharge high frequency power source 4 is connected through a matching reactance 5 to an upper electrode 2a, and a lower electrode 2b is grounded to execute a discharge. Thus, the thickness of the lower part 1b of the tube is reduced thinner than that of the upper part 1a to provide the effect of a ballast capacitor at the dielectric part of the upper part 1a, the lower part 1b can be reduced at its impedance to accelerate normal discharge, thereby preventing abnormal discharge from occurring. |
