Düsseldorf 2007 – wissenschaftliches Programm
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P: Fachverband Plasmaphysik
P 7: Poster
P 7.39: Poster
Montag, 19. März 2007, 16:30–18:30, Poster A
Density profile of strongly correlated spherical Yukawa plasmas — •Christian Henning1, Michael Bonitz1, Alexander Piel2, Patrick Ludwig1,3, Henning Baumgartner1, and Volodymyr Golubnichiy1 — 1CAU zu Kiel, ITAP, D-24118 Kiel — 2CAU zu Kiel, IEAP, D-24118 Kiel — 3Universität Rostock, Institut für Physik, D-18051 Rostock
Recently the discovery of 3D dust crystals, so-called ``Yukawa balls" [1], excited intensive experimental and theoretical activities. The shell structure of these crystals, including details of the shell radii and the particle distribution over the shells has been very well explained theoretically by a simple model involving an isotropic Yukawa-type pair repulsion and an external harmonic confinement potential [2]. So far an open question is the average particle distribution, i.e. how does the radial density profile look like. It is well known that in the case of Coulomb interacting particles in a harmonic potential the answer is given by a constant density. Here, we extend this analysis to a plasma with Yukawa interacting particles. We show that screening has a dramatic effect on the density profile, which we derive analytically for the ground state in meanfield approximation [3]. Interestingly the result applies not only to a continuous plasma distribution but also agrees well with simulation data for the Yukawa crystals exhibiting the above mentioned shell structure.
[1] O. Arp et al., Phys. Rev. Lett. 93, 165004 (2004)
[2] M. Bonitz et al., Phys. Rev. Lett. 96, 075001 (2006)
[3] C. Henning et al., Phys. Rev. E 74, 056403 (2006)