Influence of Resonance Radiation Transport on Chemical Equilibrium in an Argon Arc

Deviations from chemical equilibrium in argon arc plasma are analysed by means of collisional-radiative model. Corresponding comprehensive kinetic scheme has been developed and applied form study of free-burning arc at the conditions typical for welding applications. While the natural lifetime have been used for radiation emitted from highly excited argon states, the resonance radiation was described taking into account the radiation transport effects. Resulting spatial distributions of excited argon atoms are compared for the cases of LTE and two-temperature plasma using different approaches for the description of the resonance radiation transport

Advanced Approach for Radiation Transport Description in 3D Collisional-radiative Models

The description of radiation transport phenomena in the frames of collisional-radiative models requires the solution of Holstein-Biberman equation. An advanced solutuion method for 3D plasma obejcts is proposed. The method is applicable for various line contours in a wide range of absorption coefficients. Developed approach is based on discretization of the arbitrary plasma volume on a Cartesian voxel grid. Transport of photons between the cells is computed using the ray traversal algorithm by Amanatides [1]. Solution of the particle balance equations with computed in advance radiative transfer matrix is demonstrated for various typical arc shapes, like e.g. free-burning arc and cylindric arc. Results are compared with corresponding calculations using previously developed approaches. As the method is suited for finite geometries and allows for a strict solution of the radiation transport equation, applicability ranges of previous approximations can be specified

Effect of Resonance Radiation Trapping on the Excited State Densities in Free-Burning Arc Plasmas

Modern arc models takes into account collisional-radiative schemes for better agreement with experiment [1]. Radiation transport phenomena play an important role in redistribution of excited species densities. Influence of resonance radiation transport on spatial distribution of excited atoms in argon arc plasma was studied by numerical model. Solution of the Holstein-Biberman equation was based on the matrix method [2]. Results are compared with conventional effective lifetime approach

DUST PARTICLE CHARGE DETERMINATION IN CONSIDERATION OF NON-LOCAL EFFECTS IN A STRATIFIED GLOW DISCHARGE

A new theoretical method of dust particle charge determination is provided. This method is based on the calculation of the ion and electron fluxes on the dust particle surface in a spatially periodic strata field. The electron flux is calculated through the non-local electron distribution function (EDF), which is formed by inhomogeneous strata potential. The comparison between proposed theoretical method and the traditional method of using Maxwell EDF for dust particle charge calculation is done87-8

Electron density stratification in two-dimensional structures tuned by electric field

A new kinetic instability which results in formation of charge density waves is proposed. The instability is of a purely classical nature. A spatial period of arising space-charge and field configuration is inversely proportional to electric field and can be tuned by applied voltage. The instability has no interpretation in the framework of traditional hydrodynamic approach, since it arises from modulation of an electron distribution function both in coordinate and energy spaces. The phenomenon can be observed in thin 2D nanostructures at relatively low electron density.Comment: 4 pages, 2 figure

DUST PARTICLE CHARGE DETERMINATION IN CONSIDERATION OF NON-LOCAL EFFECTS IN A STRATIFIED GLOW DISCHARGE

87-87A new theoretical method of dust particle charge determination is provided. This method is based on the calculation of the ion and electron fluxes on the dust particle surface in a spatially periodic strata field. The electron flux is calculated through the non-local electron distribution function (EDF), which is formed by inhomogeneous strata potential. The comparison between proposed theoretical method and the traditional method of using Maxwell EDF for dust particle charge calculation is don