New Method for the Determination of the Electron Temperature from Langmuir Probe Characteristics

摘要

The electron retarding current collected by a Langmuir probe in a plasma possessing a Maxwellian electron energy distribution function is a an exponential function. If such a current is smoothed by a non-recursive filter the result is a product of the original current and a factor independent on probe voltage. This leads to a shift between the floating potentials of smoothed and unsmoothed probe current from which the electron temperature V_e may be obtained. A suitable smoothing filter is chosen and all means necessary for the practical realization of the method are given. The influence of the ion current on the determined value of V_e is investigated. The convenience of the method is shown by means of testing calculations and a measuring example (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)