Aachen PK 2003 – wissenschaftliches Programm
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P: Plasmaphysik
P 17: Poster III
P 17.38: Poster
Donnerstag, 20. März 2003, 17:30–19:15, Foyer
The ion drag force on micrometer sized particles at high and low ion energies — •Markus Hirt and Alexander Piel — IEAP, AG Plasmadynamik, Christian-Albrechts-Universität, 24098 Kiel
Micrometer sized particles in a plasma attain high negative charge (60000 qe at 25 µm dia.), which lead to appreciable momentum transfer between moving ions and the particle by ion collection or scattering. The so-called ion drag force [Barnes et al. 1992] is an important mechanism in complex (dusty) plasmas, which governs the transport of microparticles or can lead to the formation of dust-free regions (voids). Here we discuss the experimental results obtained in the DODO device (described in a companion paper), where the trajectories of free falling glass microballoons are deflected by a large area ion beam or by a subsonic ion wind. The results are critically compared with standard models [Barnes et al. 1992, Kilgore et al. 1993, Daugherty and Graves 1995] and with recent extensions [Khrapak et al. 2002] that suggest a dramatic enhancement of the ion drag force at low energies.