Tuning the electron temperature of a nitrogen plasma by adding helium and argon

Abstract

Using the global model and its concomitant profile shape factor and recent experimental ionization cross section, calculation of the electron temperature, Te, is carried out as a function of the mixing ratio in two-species N2/Ar and N2/He plasmas. The result is compared with measured values determined by the line-ratio technique in an inductively coupled plasma. The overall trend of the variation of the measured electron temperature is well described by the model: they agree in the N2/He plasma and the calculated Te becomes increasingly lower at higher argon partial pressure, up to ∼20% for a pure argon plasma. A second method uses an empirically determined profile shape factor for a pure nitrogen plasma and calculates the change of electron temperature due to the addition of inert gas. Except for the pure helium case, the difference between the measured and calculated value is <10% in the entire range of mixing ratio.