Hollow anode plasma source for high-current electron beam generation.

We report on results of a large cross-sectional area ($\sim$ 170 cm$^{2}$), high-current ($\sim 1000$A), uniform electron beam generation using a hollow anode plasma source at pressure of $^{5} \quad 8\times 10^{-5}$ Torr, in a diode supplied with an accelerating pulse of 300 kV and 300 ns duration. The hollow anode discharge was sustained for $\sim$ 10 $\mu$s by seven BaTi based ferroelectric plasma sources. The resistive decoupling of each plasma source produces a uniform plasma density distribution at the hollow anode output grid at a discharge current $\le 1000$A. It was found that the hollow anode plasma is characterized by a density of $\sim 10^{12}$ cm$^{-3}$, an electron temperature of $\sim 8$ eV and a group of fast electrons with energy of $\sim 50$ eV. It was shown that an increase in the hollow anode output grid potential allows one to significantly reduce the plasma pre-filling of the accelerating gap.