Emissive probe diagnostics in low temperature plasma - Effect of space charge and variations of electron saturation current

We report a study of electron saturation current variations at varying probe heating that were found to be closely related to probe wire contamination. The study was performed in three types of low temperature argon plasma - the weakly magnetized plasma of a cylindrical magnetron, the non-magnetized plasma of a double plasma machine and a hollow cathode plasma jet, showing different trends. In the present work the effect of overestimation of the plasma potential by a strongly emitting probe is discussed and experimental data are compared with a theoretical model. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.