Spark gap switch with jet pump driven gas flow

Abstract

A spark gap switch is disclosed with a pumping system which utilizes flowing gas to replenish the interelectrode region between conductive pulses. The spark gap switch typically consists of a housing enclosing a gas filled chamber in which there are two end electrodes with an intervening trigger plane electrode that may be inserted at other than midplane. To initiate switch closure, a trigger pulse is applied between one end electrode and a trigger plane electrode causing the gas in the intervening gap to ionize and conduct and thereby bring on complete switch closure. To achieve proper gas flow each end electrode is configured as a truncated cone and gas is caused to flow from a multiplicity of ports spaced equidistantly around each cone base. The gas ascends the conical outer surface of each end electrode, sweeps over the crown and exhausts out through an opening in the center of each electrode. From a small plenum in the base of each end electrode some of the gas is exhausted out of the system while the larger fraction is recirculated. Recirculation is accomplished by jet pumps using pressurized fresh gas streaming from nozzles within the base plate structure of each end electrode to draw exhaust gas into mixing chambers. The resulting mixture of new and exhaust gas flows out of the multiplicity of ports spaced equidistantly around the base of each end electrode. The flow rate is controlled so that the flush factors are the same on each end electrode.