Progress in Plasma Processing of Materials, 2001

ISBN Print: 1-56700-165-3

OPTICAL DIAGNOSTIC TECHNIQUES FOR A THERMAL RF DISCHARGE USED FOR PLASMA FLASH EVAPORATION

DOI: 10.1615/ITPPC-2000.90
pages 63-68

Resumo

The flash evaporation process of zirconia powder injected into a thermal RF plasma is investigated by means of three optical diagnostic techniques: Imaging spectroscopy for temperature measurements, monochromatic imaging for recording the intensity distribution belonging to different species in the plasma and laser Doppler anemometry for velocity determination. The influence of the discharge pressure on particle evaporation is investigated. While the temperature only weakly changes with rising pressure, a strong increased emission can be observed. This is due to a decrease of particle velocities an thus longer residence times in the plasma accompanied with an enhanced evaporation.