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In the present work, a numerical study of the influence of discharge current, gas pressure, and axial magnetic field on the formation of the spatial distributions of parameters of a dusty argon plasma of the positive column of a dc glow discharge is reported. It is found that an increase in current, pressure, or magnetic field enhances the degree of dust influence on the spatial distribution of particles and on the fluxes in the plasma and can lead to the implementation of a variety of outcomes from the flattening of the radial density profile of charged particles to the formation of uniform and even nonmonotonic radial distributions with the reversal of the ambipolar field direction. Three different modes of transition to nonmonotonic radial density profiles, depending on the parameter being changed, are reported. [ABSTRACT FROM AUTHOR]

In this article, the results of numerical simulation regarding the influence of different dust particles’ spatial distributions in the plasma of a positive column (PC) of direct current glow discharge in argon are presented. The effect of homogeneous dust clouds of different radii located on the axis of a gas discharge tube, uniform annular clouds of dust particles, and clouds with inhomogeneous dust density on the formation of the main scenarios of radial distributions of particles and fluxes in the PC plasma was studied for a wide range of dust particle densities. It was found that similar (when all three density profiles of electrons, ions, and charged dust inside the dust cloud are parallel) and nonmonotonic radial distributions of charged particles are formed only when the external region between the boundary of the dust cloud and the wall of the tube is of sufficient size to provide the necessary level of ionization to maintain a fixed discharge current. The possibility of the formation of nonmonotonic charge profiles in the case of increasing and falling nonmonotonic distributions of the dust grains is shown. [ABSTRACT FROM AUTHOR]