The effects of mass flow rate and electrode divergence angle on the performance of gas-blown spark gap switches

The effects of mass flow rate and electrode divergence angle on the performance of a gas-blown spark gap switch operated in the self-breakdown repetitive mode are presented. The switch was flushed with a two-dimensional, laminar flow directed between a diverging pair of electrodes. Voltage versus t i a e data were obtained for two average flow velocities, based on the flow area at the point of minimum electrode separation, of 4.1 and 8.2 m/s. The two divergence angles used were 5 and 10 degrees, and the minimum electrode separation distance was 2.54 ma. High-speed interferograms showing density variations in the gas were obtained and linked with the voltage data in order to identify various types of breakdown events and to develop both qualitative and quantitative definitions for use in the reduction of the data. From the analysis of the data, it was determined that an increase in either the mass flow rate or the electrode divergence angle improved switch performance by reducing the percentage of switch closures which were considered failures.