Electric field reversal in near-cathode region of glow discharge in helium

Kudryavtsev, A. A.; Nisimov, S. U.; Prokhorova, E. I.; Slyshov, A. G.

doi:10.1134/s1063785011090112

Cited by 8 publications

(3 citation statements)

References 3 publications

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“…While the presence of the reversed field bears some similarity with the case of the negative glow region of dc glow discharges [52][53][54], in that setting fast electrons arriving from the sheath can interact with the trapped population and can eventually increase the energy of some of the electrons, enabling them this way to get released from the trap. This effect is the result of Coulomb collisions, which are however, not included in the present simulation.…”

Section: Transport In Periodically Modulated Electric Field In Argonmentioning

confidence: 97%

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N₂ and their mixtures

Albert

Bošnjaković

Dujko

2021

J. Phys. D: Appl. Phys.

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The relaxation of the distribution function of the electrons drifting under the influence of a homogeneous electric field in noble gases is known to take place over an extended spatial domain at ‘intermediate’ values of the reduced electric field, E/N. We investigate the transport of electrons in Ar and N2 gases, as well as in their mixtures at such E/N values (∼10–40 Td). After discussing briefly the basic scenario of relaxation in a homogeneous electric field, the major part of work concentrates on the properties of transport in an electric field that is spatially modulated within a finite region that obeys periodic boundaries. The spatial distribution of the mean velocity, the mean energy, and the density of the electrons, the importance of the excitation channels, as well as the electron energy distribution function are obtained from Monte Carlo simulations for various lengths of the computational domain, at different mean values and degrees of modulation of the reduced electric field. At low modulations, the spatial profiles of the mean velocity and mean energy are nearly harmonic, however their phases with respect to the electric field perturbation exhibit a complex behaviour as a function of the parameters. With increasing modulation, an increasing higher harmonic content of these profiles is observed and at high modulations where an electric field reversal occurs, we observe trapping of a significant population of the electrons. The effect of mixing a molecular gas, N2, to Ar on the transport characteristics is also examined. Transition to local transport at high N2 admixture concentrations and long spatial domains is observed.

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Section: Transport In Periodically Modulated Electric Field In Argonmentioning

confidence: 97%

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N₂ and their mixtures

Albert

Bošnjaković

Dujko

2021

J. Phys. D: Appl. Phys.

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“…Consequently, after a sufficiently long time all electrons are expected to be trapped in our simulation. While the presence of the reversed field bears some similarity with the case of the negative glow region of dc glow discharges [46][47][48], in that setting fast electrons arriving from the sheath can interact with the trapped population and can eventually increase the energy of some of the electrons, enabling them this way to get released from the trap. This effect is the result of Coulomb collisions, which are however, not included in the present simulation.…”

Section: Transport In Periodically Modulated Electric Field In Argonmentioning

confidence: 97%

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N$_2$ and their mixtures

Albert¹,

Bošnjaković²,

Dujko³

2020

Preprint

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The relaxation of the distribution function of the electrons drifting under the influence of a homogeneous electric field in noble gases is known to take place over an extended spatial domain at 'intermediate' values of the reduced electric field, E/N . We investigate the transport of electrons in Ar and N 2 gases, as well as in their mixtures at such E/N values (∼ 10-40 Td). After discussing briefly the basic scenario of relaxation in a homogeneous electric field, the major part of work concentrates on the properties of transport in an electric field that is spatially modulated within a finite region that obeys periodic boundaries. The spatial distribution of the mean velocity, the mean energy, and the density of the electrons, the importance of the excitation channels, as well as the electron energy distribution function are obtained from Monte Carlo simulations for various lengths of the computational domain, at different mean values and degrees of modulation of the reduced electric field. At low modulations, the spatial profiles of the mean velocity and mean energy are nearly harmonic, however their phases with respect to the electric field perturbation exhibit a complex behaviour as a function of the parameters. With increasing modulation, an increasing higher harmonic content of these profiles is observed and at high modulations where an electric field reversal occurs, we observe trapping of a significant population of the electrons. The effect of mixing a molecular gas, N 2 , to Ar on the transport characteristics is also examined. Transition to local transport at high N 2 admixture concentrations and long spatial domains is observed.

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“…离子密度达到极值, 离子密度的梯度为零, 同时电场强度为零, 此处离子电流密度为零, 故总电流密度即等于电子电流密度( ) [95] , 如图9(e) 和图9(f)所示. 根据文献 [96][97][98][99], 电场反转的位置与放电空间中离子密度最大值位置、电势极值位置…”

Section: 密度(unclassified

Numerical simulation study on microdischarge via a unified fluid model

Wang,

Zhao,

2024

Acta Phys. Sin.

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Numerical simulation has become an indispensable tool in the study of gas discharge. However, it is typically employed to reveal microscopic properties in a discharge under specific conditions. In this work, a unified fluid model for discharge simulation is introduced in detail. The model includes the continuity equation, the energy conservation equation of the species (electrons and heavy particles), and Poisson's equation. The model takes into account processes such as cathode electron emission (secondary electron emission and thermal emission), reaction enthalpy change, gas heating, and cathode heat conduction. The full CVC curve encompasses a range of discharge regimes, such as the Geiger-Muller regime, Townsend discharge, subnormal glow discharge, normal glow discharge, abnormal glow discharge, and arc discharge. The obtained CVC curve is consistent with the results in the literature, confirming the validity of the unified fluid model. On this basis, the CVC curves are obtained at a wide range of pressures (50 Torr-3000 Torr) conditions. Simulation studies are conducted with a focus on the discharge characteristics for microgap of 400 μm and at pressures of 50 Torr and 500 Torr, respectively. The distributions of typical discharge parameters under different pressure conditions are analyzed by comparison. The results indicate that the electric field in the discharge gap is uniform in the Townsend discharge regime, and the space charge effect can be ignored. The cathode fall and the quasi-neutral regions appear in the glow discharge, and the space charge effect is significant. In particular, the electric field reversal occurs in the abnormal discharge regime due to the heightened particle density gradient. The electron density reaches approximately 1022 m-3 in the arc discharge regime dominated by thermal emission and thermal ionization, as the increase of the current density. The gas temperature peak is 11850 K when the pressure is 500 Torr, and the cathode surface temperature is heated to 400 K due to heat conduction. The present model can realize the simulation of gas discharge across a wide range of condition parameter regimes, which promotes and expands the application of fluid models and aids in achieving a more comprehensive investigation of discharge parameter properties.

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Electric field reversal in near-cathode region of glow discharge in helium

Cited by 8 publications

References 3 publications

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N₂ and their mixtures

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N₂ and their mixtures

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N$_2$ and their mixtures

Numerical simulation study on microdischarge via a unified fluid model

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Electric field reversal in near-cathode region of glow discharge in helium

Cited by 8 publications

References 3 publications

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N2 and their mixtures

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N2 and their mixtures

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N$_2$ and their mixtures

Numerical simulation study on microdischarge via a unified fluid model

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Product

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Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N₂ and their mixtures

Monte Carlo simulation of resonance effects of electron transport in a spatially modulated electric field in Ar, N₂ and their mixtures