Pollution of lens in high pressure SF₆ gas for high-voltage, high-current, laser triggered switch

The surface damage of the lens in high voltage, high current laser triggered gas switch is analyzed, based on the measurements of optical transmission, the analysis of the mist material on the lens surface and the statistic of exposure time. Both the corrosion and the debris/dust deposition on the lens surface have some effect on the optical transmission, which leads to the failure. From the comparison of three different structure laser triggered switches and the statistics of their operation data, it is concluded that both HF and debris/dust can be greatly eliminated by using the CaF2 lens, low water imbibitions insulation materials, and tungsten-copper electrode. The operation time of the switch can be prolonged with dehydration processing of the components. The axial insulated V/N type assistant multilevel gap switch has the longest operation life.