Laser triggered switching of a pulsed, charged, oil filled spark gap

A focused, Q-spoiled laser, aligned along the interelectrode axis of a pulse charged switch assembly, was used to initiate the conduction of an overvolted transformer oil filled gap. Laser power varied between 5 and 200 MW and the voltage pulse exhibited a risetime of 500 nsec to a voltage of 700 kV. A parametric study of the factors affecting the delay between the laser pulse arrival at the gap and conduction of the gap was accomplished, in which the effects of the focal point location, laser power, switch polarity, and voltage on the gap at laser arrival were determined. Delay times as short as 12 nsec were recorded with jitter, a measure of reproducibility, in the low nanosecond region.