Langmuir Probe in Non‐Maxwellian Plasma: Correlation Between the Electron Energy Distribution Function, the Ion Energy at the Sheath Edge and the Floating Voltage

This work is devoted to the study of the Langmuir probe in non-Maxwellian plasma, assuming mono-energetic singly charged ions and a collisionless sheath. Using a general analytical equation for the Electron Energy Distribution Function (EEDF), we study the effect of the EEDF profile on: a) The ion energy at the sheath edge of a negatively biased collector, b) the I-V probe characteristic and c) the floating voltage (Vp-Vf). Different methods are used and compared to determine these parameters or characteristics. A correlation is given between the floating voltage, the ion energy at the sheath edge and the EEDF profile. The study is also extended to distribution functions with several components. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)