Investigation of the Dynamics of a Microstructured Spark Channel in Air in the “Tip (Anode)–Plane” Geometry at the Stage of Radial Expansion

Fast shadow visualization of a pulsed discharge in a short gas gap

“…The velocity corresponding to this section (below 250 ns) on our diagram is ∼ (4 − 5) • 10 2 m/s. The authors of paper [20] observed during self-breakdown of a short gas gap in with similar geometry of the electrode system immediately after the start of the system formation of microchannels broadening at the same velocity, up to the moment of the channels merging in 20 ns after the start. Using the data of the authors of the paper [4], one can estimate the temperature and relative compaction of the medium behind the shock wave front.…”

Near-cathode plasma and gas-dynamic processes during the formation of a spark discharge in air at atmospheric pressure in the gap point-plane

“…Since pulse high-voltage atmospheric-pressure discharges are used widely in practice, they have been studied extensively for a long time. Such discharges are characterized by distinct gas dynamics, which may evolve over nanosecond timescales and may be examined using shadow techniques (see [1][2][3][4][5][6][7][8][9][10] and references therein).…”

“…Using laser probing and interference techniques, the authors of more recent papers [5][6][7][8][9][10] examined a spark discharge in the point−plane geometry in air and found that its microstructure features a multitude of microchannels. Additional studies of gas dynamics were also performed: the dynamics of formation of the above-mentioned radial structure of the discharge channel was detailed [7,8], and hemispherical SWs with their sources located on the surface of a planar electrode were detected [6].…”

“…A single-frame shadow photography technique was used in [5][6][7][8]. This limited the potential to examine the dynamics of gas-discharge processes.…”

“…The experimental procedure for the point−plane discharge geometry in atmospheric-pressure air and the experimental equipment were discussed in detail in [5][6][7][8]11]. A negative pulse with an amplitude of 25 kV and a duration of 7 ns was applied to the discharge gap via a 7-m-long cable.…”