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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.45: Poster

Donnerstag, 29. März 2001, 15:45–18:15, Foyer S\ 3

Instabilities of the resonance attractor for spiral waves — •Vladimir S. Zykov¹, On-Uma Kheowan², and Stefan C. Müller¹ — ¹Institut für Experimentelle Physik, Otto-von-Guericke-Universität, Universitätsplatz 2, D-39106 Magdeburg, Germany — ²Mahidol University, Department of Chemistry, Rama 6 Road, Bangkok 10400, Thailand

Spiral waves induced in a thin layer of the light-sensitive Belousov-Zhabotinsky reaction can be controlled by application of short light pulses at instants corresponding to the passage of a wave front through a measuring point. Our theoretical and experimental studies demonstrate that such a feedback leads to a drift of the spiral wave core along a discrete set of stable circular trajectories centered at the measuring point. Further analysis indicates, that the circular orbits become unstable when the amplitude of the external forcing is too strong and/or the time delay in the feedback loop is too long. This instability occurs due to a Hopf bifurcation and results in a wide variety of fascinating trajectories of the spiral wave core.