| 摘要 |
PURPOSE:To increase preliminary ionization capability by arranging a third electrode between a first and a second electrode facing each other, and generating main discharge between the second and the third electrode with charged particles generated by the preliminary ionization between the first and the third electrode. CONSTITUTION:When a switch of a charging and discharging circuit 20 is opened, a charging and discharging capacitor C10 is charged. By closing a switch 21, the charge stored in the capacitor C10 transfers to each of the discharging capacitors CP1, CP2. As the result of the above transfer, corona discharge generates between a lead wire 13 and a glass tube 14. By this corona discharge, trigger discharge is induced in a discharging space A between the first electrode 10 and the third electrode 12, and charged particles are supplied to a discharging space B. Since, in the above state, a high voltage is applied between the second electrode 11 and the third electrode 12 from a high voltage power supply H.V, gas laser medium between the electrodes 11 and 12 is excited, so that main discharge generates between the electrode 11 and the electrode 12. By this constitution, preliminary ionization capability is increased, and the life of the glass tube 14 is lengthened. |
