Complete parametrization of the plasma-sheath transition and I–V curves for a cylindrical or spherical Langmuir probe according to the features of the probe, simultaneously including geometry, ionization and collisions

Abstract

This paper solves and analyses the complete characterization of the plasma-sheath transition and the characteristic I–V curves of an active and collisional plasma close to a cylindrical or spherical wall considering a wide range of the parameter which describe the model to be useful for experimental measures. Despite the difficulty of including the three possible pre-sheath mechanisms, this characterization is obtained from a self-consistent model using three easily measurable parameters, namely the electric potential of the wall, the positive ion current collected by the wall, and the radius of the wall. These parameters are easy to measure and facilitate the diagnosis of plasmas from an experimental point of view.