High-current large-area uniform electron beam generation by a grid-controlled hollow anode with multiple-ferroelectric-plasma-source ignition

Abstract

We report results on the generation of a large-cross-section (about 170 cm2) high-current (about 1000 A) uniform electron beam by a hollow anode (HA) plasma source at a pressure of approximately 8 × 10−5 Torr, in a diode with an accelerating pulse of 300 kV and approximately 300 ns duration. The HA discharge was sustained for about 10 μs by seven Ba–Ti-based ferroelectric plasma sources. The resistive decoupling of each plasma source produces a uniform plasma density distribution at the HA output grid at a discharge current of not more than 1000 A. It was found that the HA plasma is characterized by a density of about 1012 cm−3, an electron temperature of approximately 8 eV and a group of fast electrons with an energy of about 50 eV. It was shown that an increase in the HA output grid potential allows the plasma prefilling of the accelerating gap to be reduced significantly.