Electron temperature measurements in medium electron density plasmas

Abstract

This paper reports the results of the spectroscopic electron temperature ( T e) measurements in plasmas with electron densities ranging (0.3–1.4)×10 17 cm −3. The results of T e measurements obtained from various spectroscopic methods are mutually compared and discussed in relation to the condition for partial local thermodynamic equilibrium (PLTE). For the cases when the application of the spectroscopic techniques for T e measurements cannot be justified on the bases of PLTE criterion, new method for determination of plasma electron temperature is proposed and tested. Measurements of plasma parameters, electron temperature and electron density were performed in a low-pressure pulsed arc in helium with small admixture of nitrogen or oxygen whose ions were used as thermometric species. The electron densities were determined from the width of the He II P α 468.6 nm line.