Column Of Low-pressure Glow Discharge Research Articles

Theoretical Analysis of Magnetic Pinch Glow Discharge Plasma at Low Pressure

In the process of electron beam and plasma interaction, the angular magnetic field produced by the electron beam affects the physical parameters of the plasma. In this paper, first, the Thomson ionization coefficient under the condition of cross field is derived. Second, based on a magnetohydrodynamics method, the axial distribution of plasma density in the positive column of low-pressure glow discharge under the magnetic field is deduced, and the effect of the angular magnetic field on glow discharge plasma is studied. Finally, the above results are verified by numerical simulation. The results show that when the pressure is 10 Pa, the plasma density first increases and then decreases with the increase of magnetic field. When the pressure is 0.1 Pa, the plasma density decreases with the increase of magnetic field.

Parameters of the positive column of glow discharge with dust particles

We calculate the measured nonlocal parameters of the plasma of the positive column of direct current glow discharge in the presence of dust structures with different dust particle concentrations. The calculations are performed for typical conditions of the positive column of low-pressure glow discharge in air at which a collisional regime of maintaining discharge is achieved. The discharge plasma is described using the diffusion approximation; the flows to the surface of the dust particles are described in the orbital motion limited approximation. Calculation is carried out for micron-size particles with concentrations of up to 1011 m−3. The distribution of the dust component is assumed to be independent of the discharge parameters. Radial distributions of the plasma components and of the electric field component are obtained. The charges of dust particles for various concentrations and discharge parameters are calculated. It is demonstrated that for a certain particle concentration, the absorption efficiency of plasma particles becomes comparable with diffusion losses at the tube walls. The influence of the dust cloud on the electric field configuration at different dust particle concentrations in the cloud is analyzed. The current-voltage characteristics of the positive column of glow discharge are calculated. A higher discharge stability toward the perturbative action of dust particles at high discharge current values is demonstrated.