Plasma Diagnostics - Electrical Probes

Abstract

The electric (or Langmuir) probe is one of the simplest plasma diagnostic tools, which can measure the spatial and temporal variations of electron temperature, plasma density, electron energy distribution, plasma potential, flow velocity, ion temperature, fluctuations with simple geometry. It is simple in geometry, yet very complicate in theory. As for the standard introduction, the following conventional, yet still used and to be updated, probes are explained: single, double, triple and emissive probes in un-magnetized, magnetized, DC and/or RF plasmas. As for the challenging probes, Mach and Visco-Mach probes are also introduced.