DETERMINATION OF ELECTRON-TEMPERATURE IN ION PLATING DISCHARGES BY OPTICAL-EMISSION SPECTROSCOPY

By the use of Optical Emission Spectroscopy (OES), the electron temperature, T(e), is estimated for argon based dc diode and thermionic triode discharge plasmas. In addition, the dependence of T(e) on the presence of electron beam evaporated titanium in the plasma is investigated. The difficulties associated with calibration when determining T(e) by OES are highlighted; the uncertainties influence calculated T(e) values in relative and absolute terms. Nevertheless, our results indicate that (i) T(e) may rise when discharge enhancement by thermionic emission is utilised, and (ii) T(e) could be increased significantly by metal evaporation. The implications of these findings are discussed.