Measurement of ion temperatures in a large-diameter electron cyclotron resonance plasma

Abstract

The ion temperature in a large-diameter electron cyclotron resonance plasma is measured using high-resolution optical emission spectroscopy, and the correlation between the ion temperature and fluctuations observed near the chamber wall is investigated. Furthermore, the effect of multicusped fields on the ion temperature is examined. The ion temperature and the amplitude of ion saturation current fluctuations are found to decrease when multicusped fields are applied. The ion temperature and fluctuations increase with increasing incident microwave powers from 2.0 to 2.5 kW, indicating that the ion temperature is correlated with the fluctuation amplitude. The measurement of the ion saturation current fluctuation and floating potential fluctuation suggests that the fluctuations are excited by flute instability.