Necessary Preionization Timing for High Repetition Rate Operation of a High Power XeCl Laser with a Spiker-Sustainer Circuit

Abstract

Necessary preionization timing for the high repetition rate operation of a high-power XeCl laser with a spiker-sustainer circuit is investigated. A surface corona preionization scheme is applied to the spiker-sustainer circuit operating in a reverse voltage mode. It is suggested from experimental results and a simple model that if the preionized electrons are supplied at optimum timing in the sustainer charging process prior to the initiation of the spiker circuit, the preionized electrons are multiplied up to the optimum electron density to initiate a homogeneous discharge, which is indispensable in realizing a long pulse excitation of about 500 µs. Because the sustainer charging voltage is directly applied between the main electrodes during the charging process, the control of the initiation timing of preionization enables the control of the initial electron density. A maximum average power of 606 W is obtained with a pulse duration of 380 ns at a repetition rate of 794 Hz.