| Summary: | Discharge regime transition in a single pulse can present the breakdown mechanism of nanosecond pulsed dielectric barrier discharge. In this paper, regime transitions between streamer, diffuse, and surface discharges in nanosecond pulsed dielectric barrier discharge are studied experimentally using high resolution temporal−spatial spectra and instantaneous exposure images. After the triggering time of 2−10 ns, discharge was initiated with a stable initial streamer channel propagation. Then, transition of streamer-diffuse modes could be presented at the time of 10−34 ns, and a surface discharge can be formed sequentially on the dielectric plate. In order to analyze the possible reason for the varying discharge regimes in a single discharge pulse, the temporal−spatial distribution of vibrational population of molecular nitrogen N<sub>2</sub> (C<sup>3</sup>Π<sub>u</sub>, v = 0,1,2) and reduced electric field were calculated by the temporal−spatial emission spectra. It is found that at the initial time, a distorted high reduced electric field was formed near the needle electrode, which excited the initial streamer. With the initial streamer propagating to the dielectric plate, the electric field was rebuilt, which drives the transition from streamer to diffuse, and also the propagation of surface discharge.
|
|---|