Modeling, calculation and comparison of switching characteristics of a self-triggered two-electrode spark gap and a field-distortion three-electrode gaps
The article discusses the design features of a three-electrode spark gap with field distortion based on the results of an iterative calculation of the configuration and the results of a study of its time characteristics in comparison with a two-electrode spark gap and a three-electrode spark gap without calculating and equalizing the electric field in the spark gap. The design of the gap provides alternating breakdown of gaps under conditions of overvoltage and a sharp inhomogeneous electric field strength determined by the special shape of the electrodes. The spark gap is part of an experimental stand under development for the generation of neutron beams by powerful pulsed accelerators of charged particles. Taking into account the continuous operation of the accelerator about 106 repetitions, the problem of ensuring the required erosion resistance of the commutator electrodes and the stability of discharge formation without deterioration of switching characteristics is acute. Despite many years of research, no universal solution to these problems has been found. Based on the above, it became necessary to carry out this work related to the development of such gaps. The switching voltage was in the range of 147.5 - 304.5 kV with a maximum switching current of up to 87 kA. It is shown that the introduction of a distorting electrode into the spark gap during the configuration of the electric field reduces the breakdown voltage slightly (7.3-12.8%). The jitter of the response time relative to the start time of the charging pulse has been determined. The spark gap ensured the formation of a branched structure of the spark channel, which reduced electrode erosion, switching time, and voltage drop across the spark gap.