Stuttgart 2012 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 21: Poster: Staubige Plasmen

P 21.6: Poster

Donnerstag, 15. März 2012, 16:30–19:00, Poster.III

Ion-Streaming Induced Order-Disorder Transition in Multi-Component Dusty Plasmas — •Patrick Ludwig¹, Hanno Kählert¹, Michael Bonitz¹, and James Dufty² — ¹Universität Kiel — ²University of Florida

Dust Dynamics Simulations utilizing a dynamical screening approach are performed to study the effect of ion-streaming on the self-organized structures in a 3D spherically confined complex (dusty) plasma.[1,2] Varying the Mach number M – the ratio of ion drift velocity to the sound velocity, the simulations reproduce the experimentally observed cluster configurations in the two limiting cases: at M=0 strongly correlated crystalline structures consisting of nested spherical shells (Yukawa balls) and, for M≥1, flow-aligned dust chains, respectively. In addition, our simulations reveal a discontinuous transition between these two limits. It is found that already a moderate ion drift velocity (M≈0.1) destabilizes the highly ordered Yukawa balls and initiates an abrupt melting transition. The critical value of M is found to be independent of the cluster size. A similar streaming-induced order transition is expected to exist also in unconfined multi-component dusty and quantum plasmas.[3]

[1] Introduction on Complex Plasmas, M. Bonitz, N. Horing, and P. Ludwig (eds.), Springer (2010) [2] P. Ludwig, H. Kählert, and M. Bonitz, submitted to Plas. Phys. Contr. Fus. (2011) [4] P. Ludwig, M. Bonitz, H. Kählert, and J.W. Dufty, J. Phys. Conf. Series 220, 012003 (2010)