Fluid modeling of a high-voltage nanosecond pulsed xenon microdischarge

Levko, Dmitry; Raja, Laxminarayan L.

doi:10.1063/1.4959172

Cited by 18 publications

(6 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The high energy tail region can be attributed to runaway [32,33] secondary electrons that gain significant energy while traveling across the sheath and these electrons extend well into the quasi-neutral region in the microplasmas simulated in this work. Also, the PIC-MCC EEPFs could possibly be described by a bi-Maxwellian distribution with two characteristic temperatures and formulating multi-temperature models could be an important direction in improving the accuracy of continuum simulations of DC microplasma devices that are expected to have significant secondary electron emission.…”

Section: Effect Of Pd At Constant Gap Sizementioning

confidence: 68%

Benchmark continuum and kinetic simulations of argon microplasmas in the direct current and microwave regimes

Verma¹,

Alamatsaz²,

Venkattraman³

2017

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

This study presents benchmark comparisons between continuum and kinetic simulations of argon microplasmas operating in the direct current and microwave regimes. Kinetic simulations using the particle-in-cell with Monte Carlo collisions (PIC-MCC) method and continuum simulations using the full-momentum equation for both ions and electrons are performed at various operating conditions in order to study the influence of product of pressure and gap size, pd (for a given gap size), influence of gap size (for a given value of pd) and operating frequency. It is shown that using the electron energy distribution function (EEDF) predicted by zero-dimensional Boltzmann solvers (such as BOLSIG+) in continuum simulations of direct current microplasmas leads to a significant under-prediction of plasma number densities with continuum simulations based on the Maxwellian EEDF performing better particularly for higher values of pd. The discrepancy between kinetic and continuum simulations is attributed to the presence of hot electrons created as a result of secondary emission and subsequent acceleration in the sheath. On the other hand, simulations performed for argon microwave microplasmas operating at 0.5 GHz, 0.8 GHz, 2 GHz and 4 GHz demonstrated that continuum simulations performed using the rate constants from BOLSIG+ showed excellent agreement with kinetic simulations for the plasma density profiles in spite of over-predicting the voltage/power required to achieve a given plasma density.

show abstract

Section: Effect Of Pd At Constant Gap Sizementioning

confidence: 68%

Benchmark continuum and kinetic simulations of argon microplasmas in the direct current and microwave regimes

Verma¹,

Alamatsaz²,

Venkattraman³

2017

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…13,14 Levko and Raja conducted a fluid modeling of nanosecond pulsed xenon micro-discharge with sphericalprotrusion electrodes. 15 It was previously realized that the discharge behavior depends strongly not only on the cathode dimension, the working gas, or the incident power like in the low-pressure cathodes but also on the electrode material, surface roughness, and protrusions. 16,17 As for the steady-state microdischarges at atmospheric pressure, the sheath thickness plays a significant role in the discharge properties, which would be largely affected by the electric field enhancement due to the presence of the surface protrusion.…”

Section: Introductionmentioning

confidence: 99%

Effect of surface protrusion on plasma sheath properties in atmospheric microdischarges

Zhang

Verboncoeur

et al. 2018

Physics of Plasmas

View full text Add to dashboard Cite

The electric field enhancement due to the presence of cathode surface protrusion is investigated in atmospheric microdischarges with the goal of identifying the plasma sheath properties (such as cathode sheath thickness and electric field distortion). The electric field enhancement caused by surface protrusion is examined by adjusting the aspect ratio and the protrusion size. It is found that the cathode electric field enhancement depends strongly (weakly) on the aspect ratio (size) of the protrusion when it is much smaller than the discharge gap distance. In particular, the axial electric field in both vacuum and discharges becomes nonlinear with the protrusion on the cathode. The cathode sheath thicknesses obtained by two different methods are compared. With the same axial (or radial) protrusion dimension, increasing the aspect ratio will result in a significant decrease in the sheath thickness, whereas increasing the axial protrusion size with an unchanged aspect ratio will only lead to a slight decrease in the sheath thickness. The results contribute to predicting the relative plasma sheath properties from the geometrical parameter of the surface protrusion in atmospheric microdischarges.

show abstract

“…The field emission is ignored since the maximum effective electric field is much smaller than the field emission threshold (10 9 V/m). 37,38 The discharge is sustained by the ion-impact secondary electron emission from the cathode. The normal flux of electrons emitted by the cathode is related to the flux of incident ions by an effective secondary emission coefficient c eff , which is fixed at 0.1.…”

mentioning

confidence: 99%

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

Zhang

Krek

et al. 2019

Applied Physics Letters

View full text Add to dashboard Cite

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.

show abstract

Fluid modeling of a high-voltage nanosecond pulsed xenon microdischarge

Cited by 18 publications

References 12 publications

Benchmark continuum and kinetic simulations of argon microplasmas in the direct current and microwave regimes

Benchmark continuum and kinetic simulations of argon microplasmas in the direct current and microwave regimes

Effect of surface protrusion on plasma sheath properties in atmospheric microdischarges

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

Contact Info

Product

Resources

About