The gas discharge–dust particle interaction for a dc discharge in air with micron-sized particles is investigated. The plasma of the dc column is described in the frame of diffusion approximation combined with the orbital motion limited approximation for ion and electron flow on the dust component surface. The problem is solved for dust particles of 2 μm radius, embedded in a uniform glow discharge column with a diameter of 16 mm at air pressure 0.5 torr, discharge current 0.5–3 mA and particle concentration up to 105 cm−3. The current–voltage characteristics as an easy-to-observe measure of the nonlocal dust influence on the total amount of charge carriers in the discharge, as well as the radial distributions of plasma components in the dc discharge, are calculated for different dust concentrations and discharge currents. The results are compared with recently published experimental data. The presence of dust particles leads to an increase of the longitudinal electric field due to additional loss of ions and electrons. A decrease of the radial electric field within the dust cloud under the action of dust particles results in an essential change of the electron concentration profile, down to the appearance of the local minimum at the axis of the discharge.

Experimental and numerical study of positive column of glow discharge in neon with dust particles is presented. The influence of dust structures on integral parameters was measured and simulated. Spatial distributions of electrons and electric field configuration in presence of dust cloud are represented. The reverse radial electric field direction is shown to appear within the dust cloud at high dust particle concentration. The current‐voltage characteristics of discharge in neon with and without dust particles are represented. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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The diffusion/drift model of the positive column of glow discharge in neon was used for the analysis of the role of neon metastable atoms in the interaction between neon plasma and dust particles. The radial profiles of electrons and metastable atoms were simulated in the typical range of neon pressure and discharge current where dust particles may form dense dust structures changing the plasma properties. The results showed the nonlocal effect of dust particles on the plasma composition. Within the dust structure, the metastable atom concentration was shown to be higher than in the discharge without dust particles at the same discharge parameters; the ratio of concentrations of metastable atoms and electrons may increase with increasing dust particle concentration in a certain range of discharge parameters. The partial contribution of metastable atoms to the ionization was found to be higher than their losses on the surface of dust particles and increased when the gas pressure was increased.

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