Hannover 2010 – wissenschaftliches Programm
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P: Fachverband Plasmaphysik
P 7: Poster: Dusty Plasmas
P 7.4: Poster
Dienstag, 9. März 2010, 16:00–18:00, Lichthof
Spatially resolved measurements of the electric field in a rf-plasma sheath by probing with micro-particles under hyper gravity conditions — Job Beckers1, Taalke Ockenga2, Matthias Wolter2, Winfred Stoffels1, Gerrit Kroesen1, and •Holger Kersten2 — 1Eindhoven University of Technology, Department of Applied Physics, P.O.Box 513, NL-5600MB Eindhoven — 2IEAP, Universität Kiel, Leibnizstr.19, D-24098 Kiel
The electric field profile in the plasma sheath of an argon rf-plasma has been determined from measurements of the equilibrium height and the resonance frequency of plasma-confined micro-particles. In order to measure the electric field structure at any position in the plasma sheath without the plasma being changed or disturbed an additional, non-electric, force is introduced which does not alter the plasma conditions, but which does allow for manipulation of the particle position through the sheath: (hyper-)gravity, induced by a centrifuge. Consequently, the electric field and the particle charge can be determined as function of the position in the sheath, using one and the same particle for measurements at several positions throughout the sheath. Close to the sheath edge, the electric field shows non-linear behavior close to the sheath edge while the particle charge increases at positions closer to the electrode. Absolute values of the electric field at the electrode show good agreement with previous (e.g. -25.000V/m).