The repetitive operation of a spark gap column

This paper describes a series of experiments which were undertaken in order to establish the pulse repetition frequency (PRF) performance of a five stage spark gap column which was used to fire a five stage PFN Marx generator. Spark gap columns can provide a versatile and inexpensive method of firing multi-stage generators and are an alternative to using discrete switches. Also, the geometry of a spark gap column can be designed such that closure of the spark gaps in the column results in the subsequent unclosed spark gaps being irradiated. This means that the generator in which the spark gap column is used can exhibit a very stable erection process without the requirement for external UV or electrical triggering. The parameters examined which influence the PRF were the gas pressure in the spark gap column (1-5 bar), the gas type (air, SF/sub 6/, SF/sub 6//He) and the charging time constant of the generator (0.5-1.375 ms). It has been found that SF/sub 6/ possesses a faster voltage recovery time than air, and that the addition of He to SF/sub 6/ has no significant effect on the voltage recovery time. Also, the rate of rise of the voltage across a recovering spark gap is significant in the PRF performance.