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Recently, it was shown that it is possible to confine spherical dust clouds in a plasma. It was found that these dust clouds have a crystalline structure which differs noteably from the well known fcc, bcc and hcp order in extended crystalline systems. The experiments show that the particles arrange in nested shells with hexagonal order on individual shells. The high transparency and the rather slow time scales of Coulomb balls allow to observe individual particles with video microscopy techniques and therefore to determine the structural properties of Coulomb balls with high accuracy. This contribution presents a comparison of experimental results and MD-Simulations. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Dusty plasmas have been confined by glass walls in order to generate void-free particle structures under microgravity conditions. Different types of clouds establish in the cuvette in dependence on the rf power and dc bias applied to the multi-electrode system of the discharge device. The observations can be basically understood when applying standard force models to discharge simulation results. The various dust topologies are proposed to result from a change in the direction of the ion drag — inwards or outwards the cuvette gap. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]