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P: Fachverband Plasmaphysik

P 7: Complex and Dusty Plasmas

P 7.7: Poster

Montag, 13. März 2017, 16:30–18:30, HS Foyer

Electric Field Reconstruction and Particle Trapping in Nonlinear Dust-Density Waves — •Stefan Schütt¹, Michael Himpel¹, Alexander Piel², and André Melzer¹ — ¹Institute of Physics, University Greifswald — ²IEAP, University Kiel

Under laboratory conditions, micrometer-sized particles in a dusty plasma sediment in the lower discharge sheath. Under weightlessness, however, extended dust clouds can be generated and self-excited dust-density waves spanning over several wavelengths can be observed.

The dynamics of the dust particles is directly accessible by means of video microscopy. Using the reconstructed trajectories of individual particles, the potential in the wave field can be determined over a large spatial range. The decomposition into a modulation and a linear background component allows to determine the average electric field in the plasma. In this contribution, the application of this method to data obtained on parabolic flights is presented and the results are compared to numerical simulations.

In strongly non-linear dust-density waves, particles get trapped in an equilibrium of friction force and the modulated component of the electric field force. This can lead to a strongly deformed velocity distribution compared to linear waves. Molecular dynamics simulations of strongly coupled, driven waves are presented and compared to the experimental findings.