Measurement of the electron energy distribution function and the density profile of supra-thermal electrons in a hollow cathode arc

Measurements of the electron energy distribution function (EEDF) and the density profile in the near cathode region are given. Diagnostics were performed with Langmuir probes, a magnet spectrometric set-up and a 140 GHz microwave interferometer. The gas flow through the cathode was kept constant, while the pressure varied.