Studies On Magnetic-switch-controlled Discharge Circuit For Excimer Laser

Spatial uniformity and temporal stability in pulsed glow discharge are necessary toobtain high and stable pulsed energy in gas lasers pumped by pulsed discharge. The lifetimeof the upper level of excimer laser is on the level of10-8second, so laser radiation is onlypossible when the excimer laser is pumped by short pulsed discharge. Generally, rise timeshorter than150nanoseconds is required.Based on the basic principles of pulsed power technology, especially that for magneticswitch, the function modules of pulsed power circuit module were analyzed theoretically,and the related key parts such as power switch, etc., we selected according to the analysis.After studying a large number of topologies of pulsed power circuit in the literatures, apulsed circuit consisted of Fitch high voltage generator with2-staged magnetic switch wassuggested. There is capability of automatic reset in this kind of pulsed discharge, thus theusual high voltage isolation for the reset circuit can be avoided, and the low voltage resetcircuit can be used to provide a means of the pulse delay control by adjusting the resetcurrent.In the experiments of magnetic-switch-controlled pulse circuit, a method of steppingcascade analysis was applied for explaining the compression effect and the finally formedhigh-voltage pulse waveform. In the condition of tip discharge, the rising edge of the loadpulse was approximately135nanoseconds and the peak pulse voltage was about21.2kilovolts. Subsequently, when the pulsed discharge circuit was connected to a dischargechamber, reliable short pulses of fast discharge were obtained, in which the peak voltagereached about14.6kilovolts and the rising edge was approximately129nanoseconds. Thejitter of the high-voltage pulse was analyzed carefully, and it is concluded that the mainreason is the instability of charging voltage and improper reset. When the charging voltagewas increased and a reset circuit in the low voltage side was added, the delay jitter was reduced greatly.The pulsed discharge circuit suggested in the dissertation gives a new way for pulsedpower supply, the studying results will be helpful for the realization for the application inexcimer laser.