大功率CO2激光器中的气体开关触发系统

Trigger Generator for Repetition Frequency Gas Switch of High-power CO2 Laser

为提高击穿CO2激光器中大功率气体开关的稳定性,提高触发系统的效率,减小触发系统的损耗,开展了基于双管正激式电路拓扑的微秒级高电压脉冲触发系统的研究。该系统输出电压幅值〉38 kV、脉冲宽度10μs、脉冲数可控的信号击穿气体开关引燃激光器放电;设计干式脉冲变压器作为升压单元;根据反馈电路检测开关的击穿情况,通过SG3525和CD4098两种集成电路芯片设计的外围电路控制高压脉冲的输出频率和输出脉冲个数。试验结果表明：该系统在500 Hz重复频率下击穿气体开关的概率为99.7%,效率为0.2,损耗为0.88 kW;对比传统模式触发系统,击穿概率提高了2.7%,效率提高了0.12,损耗减小了1.512 kW。

In order to improve the breakdown stability of gas switch in CO2 laser, to improve the efficiency of trigger system, and to reduce the loss of trigger system, we developed a set of high-voltage pulse trigger generator（microsecond level） based on two-transistor forward topology. In the generator, high voltage pulses（the number is adjustable） with amplitude exceeding 38 kV and width of 10 μs was adopted to breakdown hyperbaric gas between electrodes of spark switch, dry-type high-voltage transformer was used as a booster unit, and the sampling and feedback control circuit that mainly consists of SG3525 and CD4098 was designed to monitor the situation of spark switch and control the frequency and number of output pulses. The experimental results show that breakdown probability of this pulse trigger generator is 99.7%, the efficiency is 0.2, and the loss is 0.88 kW, when the PRF is 500 Hz. Compared to traditional trigger system, the breakdown probability of our design is increased by 2.7%, the efficiency is increased by 0.12, and the loss is reduced by 1.512 kW.