Augsburg 2006 – scientific programme

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P: Plasmaphysik

P 27: Staubige Plasmen 3

P 27.1: Talk

Wednesday, March 29, 2006, 17:00–17:15, 1004

Particle-induced Oscillations in an Inductively Coupled Plasma — •Martin Schulze and Achim von Keudell — Arbeitsgruppe Reaktive Plasmen, Ruhr-Universität Bochum

Various unique physical properties of nanometer-sized particles make them interesting for many technological applications. The effect of dust formation in low-temperature plasmas might be exploited to develop a new kind of particle source, however, the qualities of the particles are difficult to control. The feasability of particle-induced oscillations between different heating modes as a tool to monitor and to control particle sizes and densities is being investigated.

The experiments are conducted in a GEC-cell like inductively coupled plasma (ICP) reactor. Oscillations of the plasma emission with a frequency of up to several ten Hz can be observed in different rare gas discharges in the presence of nanometer-sized particles grown during the injection of a pulse of acetylene.

This contribution presents timely and spatially resolved langmuir probe and optical emission spectroscopy (OES) measurements of the oscillations. Furthermore, ex-situ measurements of the particle size distribution and density from atomic force microscopy (AFM) and scanning electron microscopy (SEM) are shown. The evolution of the electron temperature and density calculated from the probe and OES data provide an insight into the physical nature of the instability. With the help of the AFM- and SEM-measurements the correlation between oscillation frequency and particle size distribution is explored.