The interaction between filaments in dielectric barrier discharge excited by bipolar/unipolar nanosecond pulse powers

Abstract

This study investigates the behavior of discharge filaments in dielectric barrier discharges with a focus on the effects of nanosecond pulse voltage polarity. We observed significant repulsion between discharge filaments when the pin electrode was grounded in bipolar nanosecond pulse discharge. The tilt angle of the filaments was directly proportional to the peak current, which is indicative of charge density. When the bare pin electrode acted as an H.V. electrode, the repulsion phenomenon was diminished. Surface charges released through the bare pin electrode instead of accumulated on the dielectric surface accounts for this phenomenon. The study also highlights the impact of bipolar versus unipolar nanosecond pulse powers. The addition of a water resistor (WR) results in a slower falling edge of the pulse voltage and the absence of subsequent reverse discharges. The repulsion between filaments disappears both in pin-to-ground discharge and pin-to-H.V. discharge. The introduction of WR leads to a reduction of the current pulse's duration and a premature termination of the discharge process, resulting the influence of surface charges on filament positioning negligible. It is hypothesized that the spatial distribution of ions does not exhibit significant repulsion, attributed to their substantial mass and sparse distribution in space.