Hannover 2010 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 11: Invited Talks Windisch, Manz, Loffhagen, Hauser

P 11.3: Hauptvortrag

Mittwoch, 10. März 2010, 12:00–12:30, B 305

Dynamic behaviour of dc discharges — •Detlef Loffhagen and Florian Sigeneger — INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald, Germany

Motivated by the demand to understand the basic processes and dynamics of gas discharge plasmas and by the advancement of gas discharge applications, modelling has gained increasingly in importance. Different numerical methods are in use to describe theoretically the behaviour of the gas discharge plasma including fluid (or hydrodynamic) models, a fully kinetic treatment as well as so-called hybrid methods. The present contribution deals with the numerical modelling and analysis of weakly ionized low-temperature plasmas by means of time- and space-dependent hybrid methods, which combine a fluid treatment of the plasma species with the solution of the spatially inhomogeneous electron Boltzmann equation. Main aspects of the hybrid method are given and results of its application to study the temporal evolution of spatially one-dimensional plasmas are discussed. In particular, the dynamic behaviour of the column-anode plasma of a neon glow discharge after a short disturbance of the positive column by a laser pulse is analysed from its initiation until reaching steady state. The laser-pulse induced local decrease of the ionization rate causes a strong modulation of the electric field which produces spatial structures of the particle densities and rate coefficients. These structures are closely connected with the nonlocal response of the electron component in the inhomogeneous electric field. They are typical of ionization waves with an anode-directed group velocity and a cathode-directed phase velocity.