Emissive probe measurement of electron temperature in high-pressure plasmas (≥1 mTorr)

Abstract

A new method was investigated to determine the electron temperature with the emissive probe. The basis of the method is the use of a functional relationship between the floating potential and the heating voltage of the emissive probe. A new expression for the change of the floating potential was obtained as functions of the heating voltage and the electron temperature. This expression enabled us to determine the electron temperature from the measured floating potential. An experimental verification of the present method was made at relatively high pressures (above 1 mTorr). It was shown that the electron temperatures measured by the present method were consistent with those obtained by Langmuir characteristics and that the error in them did not exceed 10%. It was emphasized, further, that the method is very attractive because the circuit required is the same as that used in potential measurement.