Characterization of Nanosecond Diffuse-Channel Discharges in Atmospheric Air

Mesyats, G.; Васенина, И.В.

doi:10.1134/s1063780x2109004x

Cited by 4 publications

(4 citation statements)

References 7 publications

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“…The same streamers were observed in Refs. [12,18,19,22,25,26,38,44,46,[49][50][51][62][63][64][65][66]. It is seen that the streamer diameter can reach the order of the length of the interelectrode distance d. Figure 2c shows that the streamer front moves in the direction of the grounded electrode at different velocities as in our previous studies [51,67].…”

Section: Positive Streamers In Air and Nitrogen At Various Pressures ...supporting

confidence: 61%

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Positive and negative streamers in air and nitrogen in a sharply inhomogeneous electric field under conditions of runaway electron generation

et al. 2022

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The development of positive and negative streamers in a point‐to‐plane gap filled with air and nitrogen at various pressures (50–200 kPa) and voltages (8–25 kV) was studied. A four‐channel intensified charge‐coupled device (ICCD) and a streak‐camera were used. Electrical parameters were measured with high resolution (10 GHz). An original method of measuring a displacement current caused by a streamer was applied. As was expected, positive streamer branches in nitrogen at low voltages and/or elevated pressures while a large‐diameter streamer is formed in air. However, at high voltages or negative polarity, the large‐diameter streamer is formed both in nitrogen and air in the entire pressure range. It was found that runaway electrons (REs) are generated in the very first picoseconds of gas ionisation near the pointed cathode. It was assumed that REs can be generated near the pointed anode and produce bremsstrahlung radiation due to a sharply inhomogeneous distribution of electrical potential. It was found that in the final stage of negative streamer development in air and nitrogen, the gas between the streamer front and the opposite electrode is ionised almost simultaneously in the entire volume when the streamer diameter is almost equal to the interelectrode gap.

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Section: Positive Streamers In Air and Nitrogen At Various Pressures ...supporting

confidence: 61%

“…The same streamers were observed in Refs. [12, 18, 19, 22, 25, 26, 38, 44, 46, 49–51, 62–66]. It is seen that the streamer diameter can reach the order of the length of the interelectrode distance d .…”

Section: Resultsmentioning

confidence: 99%

Positive and negative streamers in air and nitrogen in a sharply inhomogeneous electric field under conditions of runaway electron generation

et al. 2022

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“…However, when the discharge did occur upon initiation by single electrons [4,5], it turned out that the discharge formation time was orders of magnitude longer than that which should be in the case of a streamer breakdown [1,2]. We proposed to compare these three discharges with each other by the ratio of the gap length d to the length of the critical avalanche xk, which means an avalanche with an ion space charge field comparable to the external field [7,8]. If xk >> d, then the discharge will be Townsend; if xk ≥ d -the streamer one, and if xk << d, then the NDC discharge will occur.…”

Section: Nanosecond Diffuse-channel Dischargementioning

confidence: 99%

“…Discharges with μ = d/xk is about 10 are considered in [8]. In such discharges, avalanches initiated by external electrons reach a critical size near the cathode surface.…”

Section: Nanosecond Diffuse-channel Dischargementioning

confidence: 99%

Nanosecond discharge in atmospheric air in submillimeter gaps in a uniform electric field

Mesyats¹,

Васенина²

2022

8th International Congress on Energy Fluxes and Radiation Effects

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A nanosecond electric discharge in air in submillimeter gaps at the overvoltages up to 15-fold is under investigation. The initial electric field in such discharges is up to 106 V/cm. This field is sufficient for the electrons that initiate the discharge, as well as those obtained during the discharge, to go into the runaway mode. These electrons are called runaway electrons (RE). REs create plasma in the period 10-9 s. When the plasma density is reached of 104 cm-3, a glow discharge (GD) is initiated. The process of transition of the discharge to the GD mode lasts 10-11 s. During this time, about 5·1010 pieces of runaway electrons are formed, which, falling on the anode, lead to the formation of an X-ray beam. This beam is due to a rapid increase in the plasma density during the discharge. In the GD stage, the electric field between the cathode and the anode is divided into two parts: the cathode layer (CL) and the plasma column. The electric field in the CL exceeds 106 V/cm. At such a field, field emission (FE) from microprotrusions on the cathode surface takes place on the cathode. It leads to the explosive emission of electrons and the formation of a cathode spot and the transition of the discharge to the arc mode.

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