Characterization of trapped particles in rf plasmas

Charged dust particles electrostatically trapped in rf plasmas may exhibit kinetic energies greatly exceeding that of the surrounding gas. The high pa rticle energies are a result of charged particle interactions with local po tential fields perturbed by the presence of neighboring particles. Laser Do ppler velocimetry is used to experimentally investigate the two-dimensional dynamics of monodisperse 10.2 mu m polystyrene latex spherical particles t rapped in an argon plasma. Spatially resolved particle velocities and local particle concentrations are reported for variations in rf power and pressu re. The experimental results are compared with laser light scatter, often e mployed for studying particle dynamics. Various theories are reviewed in an attempt to interpret the experimental results. (C) 1999 American Institute of Physics. [S0021-8979(99)05716-3].