Multichannel Spark Gaps with Control Bar Electrodes: Their Development and Application (A Review)

Abstract

Multichannel low-inductance (∼1 nH) gas-filled spark gaps (MSGs)1 with several tens of channels each, bar control electrodes designed for an operating voltage of ≤100 kV, and a switched current of up to 400 kA are reviewed. The control electrodes, made in the form of narrow thin plates, have an intermediate potential, are positioned in the gap between two common main electrodes (high-voltage and low-voltage (grounded)), and are oriented uniformly along their length. Upon a near-simultaneous change in the bars' potential in a time of 0.1 MPa) of the MSG-filling gas. Electrical circuits for initiating the discharge development in the MSGs, the transients in such circuits, and the factors affecting the parameters of processes and the gap-breakdown delay and rate are considered. Particular MSG designs, multicable systems for parallel triggering of a large number of MSGs, and the use of 48 four-channel 50-kV MSGs in the first iron-free LIA-2 linear electron accelerator (2 MeV, 25 kA, and 60 ns) created in 1967 are described. The successful operation of MSGs stimulated further studies and the development of efficient trigatrons for operating voltages of 100 and 500 kV. Up to 3000 MSGs of this type are used in new high-power linear electron accelerators. A low-impedance (0.45 Ω) generator of high-voltage pulses (50–200 kV) with a multicable output has been developed to synchronously trigger such large numbers of trigatrons as these.