Soviet Research and Development of High-Power Gap Switches

Describes triggered gap R&D at Tomsk, Siberia, a world leader in high-current particle accelerators. Soviet specialists consider the triggered pressurized spark gap switch the most critical element of such accelerators. This report describes the broad theoretical foundation based on the avalanche-breakdown principle; specification of operating characteristics, including fraction of a nanosecond current rise time; and prototype construction. Either a large quantity of initiating electrons or multiple parallel gaps minimize gap inductance, further reduced by ceramic dielectric at the electrodes. Pulses down to 0.2 nanosecond at a 3 kA are possible using a fast electron beam with 3 ns pulse front and large cross section. Structures incorporating BaTi03 ceramics can deliver pulses as short as 0.6 ns at kilohertz frequencies for kA peak currents, with up to 200 hours service before disassembly. Multielectrode air-spark gaps developed for kA currents have jitter under 5 ns without gap length adjustment.