Multi-channel laser-triggered spark gap

Our capillary-discharge driver CAPEX-U [1], as many other pulsed-power devices, requires very accurate triggering of high-voltage gas switch. Laser-triggered switches offer many advantages over electrical triggered ones in terms of reproducibility, reliability, suitability for multi-gap or multi-channel operation and electrical isolation from the main high-voltage pulse. Results on the simultaneous initiation of four-channel high voltage spark gap by a neodymium dopped yttrium aluminium garnet (Nd:YAG, λ=1064 nm) laser are presented. The switch is pressurised with SF6 and N2 and holds off voltage about 500 kV at a gap separation of 13 mm. Electrical parameters of the spark channels are obtained from the comparison of experimental and modelling (equivalent circuit) results.