Characterisation of a triggered mid-plane spark gap with UV illumination

The performance of a triggered spark-gap has been investigated in which the gas and electrodes are illuminated with UV. A test circuit was produced in which the intensity and relative timing of the UV could be adjusted. The effect that this had on the voltage required to trigger the spark-gap was measured. It was demonstrated that the presence of UV reduces the required trigger voltage to initiate the closure of the spark-gap. The pulse to pulse variation of this trigger voltage is also decreased in the presence of UV. It was also shown that the relative timing between the application of the trigger pulse and the UV illumination has a marked effect on the triggering of the spark-gap. Lastly a drive circuit has been developed which selftimes the UV illumination of the spark-gap when the trigger pulse is applied and sustains the generation of UV for the duration of the trigger pulse. Results are presented demonstrating the improvement seen as a result of these design modifications.