Dust particle charging in DC glow discharge plasma

Dust particles charging in a stratified positive column of a low-pressure DC glow discharge was investigated theoretically. The presented model consists of (i) previously developed 1D selfconsistent model for discharge parameters on the tube axis; (ii) ambipolar approximation for radial electric potential distribution and the assumption that the electron energy distribution function in radial direction depends on the total electron energy only; (iii) orbital motion limited model for the processes of particle charging. For a probe particle, the 2D radial and axial charge distributions are obtained. It was shown that the particle charge strongly depends on the obtained non-Maxwellian electron energy distribution function and on the electric field distribution in the discharge tube. The obtained radial charge distribution is non-homogeneous that can lead to the complex motion of the particles, e.g., vortex motion of particles near the tube walls obtained in experiments.