Data processing of Langmuir probe I–V traces to obtain accurate electron temperature and density in Maxwellian plasmas

Abstract

The standard procedure for obtaining accurate electron temperature ([Formula: see text]) from Langmuir probe I– V characteristics measured in Maxwellian plasmas is studied by comparing the results of [Formula: see text] determined via different data-processing methods. The comparison results show that the width and position of the fitting interval in the transition region of the I– V curve as well as whether the ion collection current deducted from the I– V curve can significantly influence the calculation of [Formula: see text] and afford uncertainties in the calculation of electron density. The reasonable width of the linear fitting interval should be 30%–50% of the transition region width, and the results of [Formula: see text] are the most reliable, which are determined by the linear fitting intervals optimally selected from the electron part of I– V curves. Based on the results, a rigorous data-processing method is proposed to provide a standard procedure for obtaining reliable plasma parameters, especially accurate [Formula: see text] from Maxwellian plasmas using a Langmuir probe.