| 摘要 |
PURPOSE:To keep a preparatory ionization region constant for simplifying control of the main discharge width, by placing an insulating plate near the second main electrode between the first and second main electrodes in addition to a means for limiting an opening part in order to cut off ultraviolet rays. CONSTITUTION:An opening part 3a of the second main electrode 3 is limited by some means. Here, the opening part 3a exists only in the central part. Further, an insulator 9 is arranged in a position about 10 mm at the utmost from the second main electrode 3 between the first and second main electrodes 2 and 3. When pulse voltage is impressed from a high-voltage pulse power supply 1 between the first and second main electrodes 2 and 3, the main discharge 7 is generated having preparatory ionization electrons as a seed. A region, where this main discharge 7 is generated, almost accords with a preparatory ionization region 8. Furthermore, a laser medium is excited by this main discharge 7 so as to be able to obtain a laser beam. A sectional area of the laser beam can be controlled by limiting the preparatory ionization area 8 in this way. |
