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P: Fachverband Plasmaphysik

P 22: Poster

P 22.37: Poster

Thursday, March 22, 2007, 16:30–18:30, Poster A

Bifurcation scenarios in pattern-formation of planar gas-discharge systems — •Hans-Georg Purwins, Shalva Amiranashvili, Hendrik Bödeker, Svetlana Gurevich, and Lars Stollenwerk — Institut für Angewandte Physik, Corrensstraße 2-4, 48149 Münster, Deutschland

We investigate experimentally the luminescence radiation density and the related current density in the discharge plane of planar dc systems with high ohmic cathode and planar ac systems with dielectric barrier. We observe various kinds of qualitative changes of patterns (bifurcations) involving static and dynamic stripes, hexagons, spirals and well localized solitary spots. The observed bifurcation scenarios are very similar in ac and dc systems and in many respect they resemble to phenomena that are observed in other electrical transport systems and chemical and biological reaction-diffusion systems. The results are theoretically discussed in terms of the drift-diffusion approach and a simple reaction-diffusion equation that seems to represent a kind of normal form for the discussed class of self-organized patterns. The work has been supported by the Deutsche Forschungsgemeinschaft. http://www.uni-muenster.de/Physik.AP/Purwins/Welcome-en.html