Characteristics of a fast rise time power supply for a pulsed plasma reactor

Rotating spark gap devices for switching high-voltage direct current into a corona plasma reactor can achieve pulse rise times in the range of tens of nanoseconds. A single-gap circuit is effective for generating moderate peak voltages, but is limited by a multiple sparking phenomenon. A double-gap circuit can achieve equal peak voltages with every spark, but with a reduced number of pulses, compared to the single gap. Both configurations have an upper voltage imposed by the changing impedance of the reactor as voltage and frequency are varied. The pulse characteristics are reported for both types of circuits, along with some spectroscopic analyses. The general performance of the reactors for destruction of some compounds with both circuits is also reported. The single-gap supply is shown to provide a wider range of operating parameters than the double-gap supply but it is much more difficult to characterize the pulses, particularly their frequency, than with the double-gap supply