Studies of an artificially generated electrode effect at ground level

Abstract. The outdoor experiments, using a metallic grid above the ground surface, have yielded well-defined vertical profiles of the space-charge density. The profiles showed strong evidence for the existence of an electrode effect, which could be named the artificial electrode effect and can serve as a very useful and well-controlled model for the study of atmospheric electric processes in the atmospheric surface layer. The build-up or break-down of an electrode-effect layer occurred in a time of the order of 10 s under the experimental conditions realized. The artificially generated electrode effect is dependent on the electrical field strength supplied, wind speed, turbulent mixing and ion mobilities. Wind speed and ion mobility seem to be the dominant factors, defining space-charge density profiles. A theoretical model for the artificial electrode effect has been developed, taking into account turbulent mixing of charged particles in the air flow with the logarithmic profile of the wind velocity. The numerical analysis of the boundary value problem for the two-dimensional equations for the light ion concentrations has been performed. The model presented shows a qualitative agreement of calculated space-charge profiles with measured ones, and explains the dependence of the artificial electrode effect on the dominant control parameters. The limiting conditions for the developed theory are discussed.

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Untersuchung der Plasmagrenzschidht in einer Niederdruckentladung

Zeitschrift für Naturforschung A ◽

10.1515/zna-1962-1102 ◽

1962 ◽

Vol 17 (11) ◽

pp. 962-967 ◽

Cited By ~ 7

Author(s):

Werner Ott

Keyword(s):

Field Strength ◽

Charge Density ◽

Space Charge ◽

Debye Length ◽

Linear Increase ◽

Space Charge Density ◽

Zero Field ◽

Linear Extrapolation ◽

Electrical Field ◽

Electrical Field Strength

The electrical field in the space charge sheath between a Hg low-pressure plasma and an insulated plane wall was measured with an electron beam probe. Near the wall, the field strength was observed to increase linearly. Linear extrapolation to zero field strength is used here to define the thickness of the sheath which turned out to be 3 to 5 times the DEBYE length. On the other hand, the potential, the electrical field strength, and the space charge density in the sheath were, now, calculated (using BOHM'S criterion). Also theoretically, a (approximately) linear increase of field strength is found. A linear extrapolation of the theoretical values gives a boundary layer thickness about 6.7 to 6.9 times the DEBYE length, if the wall is at floating potential. Some differences are found between the experimental and the theoretical values of the wall potential and the space charge density in the sheath.

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Effects of particle space charge density and turbulent diffusivity on the performance of plate-plate electrostatic precipitators

Journal of Aerosol Science ◽

10.1016/0021-8502(96)00172-3 ◽

1996 ◽

Vol 27 ◽

pp. S199-S200 ◽

Cited By ~ 1

Author(s):

S.J. Park ◽

S.S. Kim

Keyword(s):

Charge Density ◽

Space Charge ◽

Space Charge Density ◽

Turbulent Diffusivity ◽

Electrostatic Precipitators

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Reconstructing the electrical structure of dust storms from locally observed electric field data

Nature Communications ◽

10.1038/s41467-020-18759-0 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Huan Zhang ◽

You-He Zhou

Keyword(s):

Electric Field ◽

Charge Density ◽

Space Charge ◽

Charge Separation ◽

Field Data ◽

Space Charge Density ◽

Dust Storms ◽

Dust Particles ◽

Electrical Structure ◽

Separation Mechanisms

Abstract While the electrification of dust storms is known to substantially affect the lifting and transport of dust particles, the electrical structure of dust storms and its underlying charge separation mechanisms are largely unclear. Here we present an inversion method, which is based on the Tikhonov regularization for inverting the electric field data collected in a near-ground observation array, to reconstruct the space-charge density and electric field in dust storms. After verifying the stability, robustness, and accuracy of the inversion procedure, we find that the reconstructed space-charge density exhibits a universal three-dimensional mosaic pattern of oppositely charged regions, probably due to the charge separation by turbulence. Furthermore, there are significant linear relationships between the reconstructed space-charge densities and measured PM10 dust concentrations at each measurement point, suggesting a multi-point large-scale charge equilibrium phenomenon in dust storms. These findings refine our understanding of charge separation mechanisms and particle transport in dust storms.

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