Influences of Target Configurations on the Working Performances of Laser Triggered Vacuum Switch

Laser triggered vacuum switch (LTVS) is one of the pulsed power switches with superior working performances compared to the other triggered switches. Previous works about LTVS illustrated that the time-delay characteristics and working life of the switch are affected by its target apparently. However, except for the influences from various physicochemical properties of target materials, there are also influences from the target configurations. And the effects of target configurations on delay time mainly involve target structures. To study the influences of different target structures on the delay time of LTVS, the electric field distribution of vacuum gaps with different target structures, including cylindrical type, conical type, and hemispherical type, are simulated. Then the test prototypes of LTVS with above three type targets are established with the detachable vacuum chamber. Effects of target configurations on the time-delay characteristics of LTVS are tested under different operating voltage and laser energy; impacts of arc ablation on the targets are also compared. The tested results suggest that, LTVS adopted conical type target shows the best time-delay characteristics compared to the other two targets, as its delay time can be controlled within 17ns and jitter within 2ns. And the targets ought to be placed at proper distance beneath the electrode to avoid the arc ablation.