| 摘要 |
PURPOSE:To enable uniform pre-ionization by separating a pin electrode pair on the upstream side of a laser gas flow to a main electrode from the main electrode at a distance where a product at the time of discharge does not reach. CONSTITUTION:Pin electrodes 14, 17 are each disposed on both sides in the cross directions of main electrodes 2, 3. A laser gas in a laser tube 1 is circulated to the electrode pair 14 from the electrode pair 17 by a fan 9. The electrode pair 17 on the up-stream side of the laser gas is mounted separated from a discharge space section 4 only at a distance where ions and electrons formed at the time of the pre-ionization discharge of the electrode pair 17 do not reach to the discharge space section 4. Accordingly, ions and electrons generated with ultraviolet rays applied from the electrode pair 17 disappear during the movement of a clearance, thus performing uniform pre-ionization, then highly repeating stable main discharge. |
