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Monodisperse electrically charged particulates (9.4 p m diameter) are trapped in the sheath of an argon RF parallel plate discharge. The particulates form Coulomb crystals consisting of horizontal hexagonal layers. A method for the determination of the charge on the particles is demonstrated that uses the response to a modulation of the electrode bias. Charges about three to five thousand elementary units are measured. The commonly applied orbital motion limited (OML) charging model leads to charges higher than the measured values. The strong coupling system is compared to the one component plasma (OCP model) and to a model with Yukawa potentials.

Experiments on dust-acoustic waves (DAW) in a magnetized anodic plasma are presented for the regime of low collisionality. The dust trapping and the self-excited and synchronized DAW dynamics are studied. Based on Langmuir and emissive probe measurements the dust confinement is found to be well described with respect to size, stability, and position of the dust cloud by an effective potential well formed by ion drag and Coulomb forces. Moreover, the measurements indicate the necessity for a kinetic model for the wave dispersion. By means of singular value decomposition the local wavelengths and growth rates of the waves are measured systematically. It is found that the measured mean wave number is well described by kinetic theory, while the theoretical growth rates overestimate the experiments. A novel observation for the DAW is a systematic variation of the wavelength inside the dust cloud.

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