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DY: Dynamik und Statistische Physik
DY 46: Poster
DY 46.45: Poster
Thursday, March 14, 2002, 15:30–18:00, D
Two-dimensional hydrodynamic model of ac gas-discharge — •G.G. Samsonidze1,2, A.L. Zanin1, and H.-G. Purwins1 — 1Westfälische Wilhelms-Universität Münster, Institut für Angewandte Physik, Corrensstr. 2/4, 48149 Münster — 2A. F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg
In certain gas-discharge parameter ranges the essential nonlinearity in the plasma response may lead to some nonlinear effects: filaments creation, their moving and interaction with each other or shock waves propagation. When the mean free path of electron-atom collisions is much shorter than the gas gap length, the hydrodynamic model may be used. The hydrodynamic description provides a resonable approximation for electron (or positive ion) concentration and velocity profiles. It is much simpler and more transparent to use than the full kinetic-theory approach based on the Boltzman equation. The hydrodynamic equations for gas-discharge species (electrons, positive ions and metastable atoms) may be derived from mass, momentum, and energy balance equations [1]. The momentum and energy relaxation caused by scattering of the gas-discharge species can be accounted for by relaxation terms in the momentum and energy conservation equations in the form of internal friction and viscosity. The electric potencial in the gas-discharge area is determined through the two-dimensional Poisson‘s equation. When electron-atom collisions are mostly ellastic energy balance equations may be neglected.
[1] L.D.Landau and E.M.Lifshitz: Fluid Mechanics, Pergamon, Oxford, 1978