Electron energy distribution functions in electron-beam-sustained discharges: application to magnetic multicusp hydrogen discharges

Abstract

Electron energy distribution functions (EDF) in magnetic multicusp H₂ discharges have been calculated by numerically solving the Boltzmann equation. Results for a 90 V, 1-10 A discharge at 40 m Torr are presented and discussed in connection with the importance of e-e Coulomb collisions, of wall losses and of the degree of dissociation affecting the EDF. Scaling laws with the discharge current, the pressure and the applied discharge voltage are presented. A satisfactory agreement is found between the calculated electron temperatures of low energy electrons ( epsilon <5 eV) and the corresponding experimental values obtained by probe techniques.