Berlin 2005 – wissenschaftliches Programm
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P: Plasmaphysik
P 23: Poster: Magnetischer Einschluß 3, Staubige Plasmen 2, Astrophysikalische Plasmen 1
P 23.16: Poster
Dienstag, 8. März 2005, 16:30–18:30, Poster HU
Three-dimensional Coulomb balls. Experiment and Theory — •O. Arp1, D. Block1, M. Bonitz2, H. Fehske3, V. Golubnychiy2, P. Ludwig2, S. Kosse2,3, A. Melzer3, and A. Piel1 — 1Institute for Experimental and Applied Physics, Christian Albrechts University Kiel, D-24098 Kiel — 2Institute for Theoretical Physics and Astrophysics, Christian Albrechts University Kiel, D-24098 Kiel — 3Institute of Physics, Ernst-Moritz-Arndt-University Greifswald, 17487 Greifswald
Recently, three-dimensional spherically symmetric mesoscopic Coulomb clusters have been successfully produced in experiments with dusty plasmas [1]. We present details of the observed “Coulomb balls“ and compare the results with computer simulations. The latter have been performed in the frame of classical Molecular dynamics using a parabolic confiment potential. We report results for the ground state shell configuration and the total energy of the clusters. Of central interest is the dependence of the cluster properties on the dust-dust interaction. Using a statically screened Coulomb potential (Debye/Yukawa) the dependence of the shell configuration on the screening length is investigated and compared with the results for an unscreeened Coulomb potential [2]. We show that the experimentally observed configuration can be accurately explained in the frame of Yukawa interaction by a suitable choice of the screening parameter.
[1] O. Arp, D. Block, A. Piel, and A. Melzer, Phys. Rev. Lett. 93, 165004 (2004) [2] P. Ludwig, S. Kosse, and M. Bonitz, Phys. Rev. E (2005), [ArXiv:physics/0409095 and physics/0409100].