Forevacuum plasma-cathode electron source for generation of a ribbon beam over a wide pressure range.

We describe the results of our investigations of the generation of a ribbon electron beam (10 × 220 mm2) by a two-stage discharge system based on a hollow-cathode glow discharge plasma. The source design enables operation in the pressure range 2 × 10-2 to 10 Pa. At a beam accelerating voltage of 8 kV, the beam current is 450 mA at a pressure of 2 × 10-2 Pa and 150 mA at a pressure of 10 Pa. To achieve a uniform current density distribution of the beam over its cross-sectional area, a special design of emission electrode was employed. This enabled us to reduce non-uniformities of the beam current density distribution to a level of 10%.