Hannover 2010 – scientific programme

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P: Fachverband Plasmaphysik

P 7: Poster: Dusty Plasmas

P 7.5: Poster

Tuesday, March 9, 2010, 16:00–18:00, Lichthof

Structural properties of confined finite dust clouds — Mattias Kroll¹, •Dietmar Block¹, Jan Schablinski¹, Tobias Miksch², Malte Passvogel², and Andre Melzer² — ¹IEAP der CAU Kiel, 24098 Kiel — ²Inst. für Physik der EMAU Greifswald, 17489 Greifswald

So far basically two different particle arrangements have been observed in 3D dust clouds. Plasma crystals which are trapped in the lower plasma sheath possess a hexagonal structure in combination with a chain formation in vertical direction while Yukawa balls show an isotropic structure of concentric shells. The difference is attributed to the directed ion flow in the sheath, which can yield to an excess of positive space charge below a negatively charged particle. However, the structure of finite dust clouds is strongly affected by the confinement as well. Our experiments allow to investigate the structural properties of finite dust clouds where a strong confinement and an ion focus are present. Thus, although the experimental conditions are similar to those of Yukawa balls their structure properties differ. This contribution discusses the similarities and differences of both systems obtained with a novel diagnostic (Stereoscopic Digital Holography).