Electron extraction from the electrostatically confined discharge source

Abstract

Electron beam current has been extracted from the electrostatically confined discharge source by applying a potential greater than the plasma potential on the focusing electrode and the Faraday cup. The effect of a convergent magnetic field, focusing electrical voltage and pressure on the extracted electron beam current have been taken into consideration. An electron current of the order of 195 /spl mu/A corresponding to a density of 6.2 mA/cm/sup 2/ has been extracted at a pressure of 2/spl times/10/sup -4/ torr, and 3 kV focusing voltage with an axial magnetic field of the order of 500 Gauss.