Kiel 2011 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 7: Poster: Modellierung und Simulation von Niederdruckplasmen

P 7.1: Poster

Dienstag, 29. März 2011, 17:00–19:00, Foyer

On the determination of electron energy transport coefficients in fluid models — •Markus M. Becker, Detlef Loffhagen, and Florian Sigeneger — INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald

Hydrodynamic models are commonly used for the theoretical description of gas discharge plasmas at moderate and high pressure. The hydrodynamic equations are frequently simplified by means of the drift-diffusion assumption for the electron particle and energy density. The diffusion and mobility coefficients for the electron particle flux can be determined in dependence on the mean energy using the local mean energy approximation. The same procedure should be used to determine the energy transport coefficients. However, the energy balance equation is often simplified by the assumption of a Maxwellian electron energy distribution function. In the present contribution, the influence of the latter approach is discussed in detail considering, as an example, a low pressure glow discharge in argon. For comparison, the spatially inhomogeneous Boltzmann equation is solved for a given interelectrode electric field. Pronounced differences between the results especially in the transition region from the cathode fall to the negative glow confirm the importance of correct energy transport coefficients. In addition, it is shown that the common heat flux approximation in full hydrodynamic models, comprising equations for density, momentum and energy, yields results that qualitatively coincide with the results of the drift-diffusion approximation assuming a Maxwellian electron energy distribution function.