Electron energy spectrum in a low pressure hollow anode discharge

Summary form only given. The electron energy distribution function (EEDF) in the far field of a low-pressure hollow anode discharge was measured. The hollow anode discharge was generated between a conical hollow anode and a spherical cathode placed at the anode axis. The EEDF was obtained from the analysis of the current collected through the retarding potential of a cylindrical electrostatic probe coaxial with the magnetic field. The transformation of the EEDF from unmagnetized to magnetized conditions was observed as the transition from a bimaxwellian ´continuum´ to a spectrum of beam-like secondary electrons, mostly at low energies, superimposed on the Maxwell distribution of the primary electrons. These low energy electrons constitute a substantial part of the total electron density, and the exact ratio depends on the discharge conditions.