Gas breakdown in atmospheric pressure microgaps with a surface protrusion on the cathode

Fu, Yangyang; Zhang, Peng; Verboncoeur, John P.

doi:10.1063/1.5037688

Cited by 31 publications

(17 citation statements)

References 37 publications

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“…In fact, many previous studies concerning microdischarges have reported that the complicated surface geometry could distort the electric field in the gap, and thus affect the breakdown mechanism and discharge characteristics. Combined with the transition of discharge modes in DBD, which is extremely sensitive to the local field intensity, it is reasonable to predict that the rough surface may lead DBD from the diffuse mode to the filamentary mode, even under one set of parameters that has been proved to trigger a uniform DBD with smooth dielectric surfaces.…”

Section: Introductionmentioning

confidence: 99%

How does the moderate wavy surface affect the discharge behavior in an atmospheric helium dielectric barrier discharge model?

Wang

Ning

Dai

et al. 2019

Plasma Processes & Polymers

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A conventional parallel-plate dielectric barrier discharge (DBD) model but with one dielectric layer having a wavy surface is purposely built for better understanding the plasma-surface interaction. The results of simulation under a kilohertz-level alternating current voltage source indicate that the surface tends to impair the discharge uniformity and stimulate complementary filamentation. Upon analyzing the detailed transient processes, it is found that the alternations of filament positions in positive and negative discharges are mainly attributed to the local residual electrons and the electric field distortion near the wavy surface.

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Section: Introductionmentioning

confidence: 99%

How does the moderate wavy surface affect the discharge behavior in an atmospheric helium dielectric barrier discharge model?

Wang

Ning

Dai

et al. 2019

Plasma Processes & Polymers

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“…One contributing factor could be the combination of various aspect ratio nonuniformities on the electrode causing an extended effective Paschen's curve. 21 The individual field emission parameters may also impact the transition from FE to PL, leading to the extended plateau, which can be investigated theoretically. One can mathematically predict the behavior of V b by coupling field emission with Townsend avalanche 22 and perform a matched asymptotic analysis to derive analytic equations in appropriate limits to demonstrate the transition between the two mechanisms.…”

Section: Introductionmentioning

confidence: 99%

The impact of cathode surface roughness and multiple breakdown events on microscale gas breakdown at atmospheric pressure

Brayfield

Fairbanks

Loveless

et al. 2019

Journal of Applied Physics

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Gas breakdown is typically driven by Townsend avalanche and predicted mathematically by Paschen's law (PL). Gas breakdown deviates from PL at microscale due to field emission, which depends critically on electrode condition; however, understanding of the impact of initial electrode surface roughness and multiple breakdown events on breakdown voltage is incomplete. This paper assesses the variation of breakdown voltage for a pin-to-plate electrode setup in air at atmospheric pressure for gap distances of 1 ± 0.5 μm, 5 ± 0.5 μm, and 10 ± 0.5 μm with different surface roughnesses. Breakdown voltage generally increases with increasing gap distance and decreasing surface roughness for a single breakdown event; however, the breakdown voltage after ten breakdown events does not depend on initial gap distance. Atomic force microscopy and optical microscopy show that multiple discharges create circular craters on the flat cathode up to 40 μm deep, with more pronounced craters created at smaller gap sizes and greater cathode surface roughness. The resulting effective gap distances (d eff , the sum of cathode placement distance and crater depth) for subsequent breakdown events are similar to those of the initially larger gap distances. Moreover, d eff becomes sufficiently large to exceed the Meek criterion for streamer formation, indicating a potential for breakdown mechanisms to change from field emission to Townsend avalanche to streamer formation for a single electrode separation distance. The resulting impact of this change in the breakdown mechanism could have significant implications for ensuring consistent microdevice operation.Published under license by AIP Publishing. https://doi.

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“…Understanding the breakdown characteristics with a given electrode morphology, as well as designing engineered electrode surface structures with desired breakdown characteristics, is important to achieve targeted system variability in microdischarge devices. In our previous studies, 31,32 microgap breakdowns were investigated with the effects of a single surface protrusion which represents a small fraction of the electrode area, while here, the main focus is on the coupling effects of a collection of protrusions on the breakdown characteristics.…”

mentioning

confidence: 99%

Gas breakdown and its scaling law in microgaps with multiple concentric cathode protrusions

Zhang

Krek

et al. 2019

Applied Physics Letters

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This paper reports gas breakdown characteristics in microgaps with multiple concentric protrusions on the cathode in the transition from the Townsend to the subnormal glow discharge regime, using a two-dimensional hydrodynamic model. The effects of the protrusion aspect ratio, height, and protrusion spacing on the breakdown voltage are investigated. The results show that when the protrusion spacing is small, the shielding effect can play a more important role in the breakdown voltage rather than the protrusion aspect ratio; the breakdown voltage is more sensitive to the protrusion height and can be assessed by the shortest gap distance. Increasing the protrusion spacing decreases the shielding effect, which lowers the breakdown voltage in both low-and high-pressure regimes. It is found that the breakdown scaling law still holds in geometrically similar microgaps with multiple cathode protrusions despite the electric field distortion.

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Gas breakdown in atmospheric pressure microgaps with a surface protrusion on the cathode

Cited by 31 publications

References 37 publications

How does the moderate wavy surface affect the discharge behavior in an atmospheric helium dielectric barrier discharge model?

How does the moderate wavy surface affect the discharge behavior in an atmospheric helium dielectric barrier discharge model?

The impact of cathode surface roughness and multiple breakdown events on microscale gas breakdown at atmospheric pressure

Gas breakdown and its scaling law in microgaps with multiple concentric cathode protrusions

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