Study on the trigger characteristics of triple-gap laser-triggered vacuum switch

Multi-gap series connection is an effective way to improve the insulation capacity of laser-triggered vacuum switch. In this paper, a triple-gap laser-triggered vacuum switch (TLTVS) is built using a detachable vacuum chamber. The TLTVS consists of a laser-triggered gap and two self-breakdown gaps. The trigger characteristics of the TLTVS are obtained under different laser energy and operating voltages through experiments. Then a simplified model for the trigger delay time is established to reveal the effect mechanism of laser energy and operating voltage. The experimental results show that the trigger delay time and the jitter time can be reduced by increasing laser energy and operating voltage, but their influence mechanisms are different. The laser energy directly affects the trigger characteristics and the discharge channel impedance of the laser-triggered gap. The latter can link the trigger process of the laser-triggered gap and that of self-breakdown gaps. The laser energy indirectly affects the trigger characteristics of self-breakdown gaps through its effect on the discharge channel impedance of the laser-triggered gap. The operating voltage mainly impacts the field current density flowing through the self-breakdown gap, which in turn affects the trigger characteristics.