The operation of a ferroelectric plasma source-assisted hollow anode (HA) electron source in a vacuum diode powered by an ∼200 kV and ∼400 ns pulsed generator was studied using time- and space-resolved laser induced fluorescence diagnostics. It was found that the plasma ion " temperature" in the vicinity of the HA output grid increases up to ∼15 eV during the accelerating pulse, which is consistent with a model of the potential screening of the grid by the randomly moving ions [Phys. Plasmas 13, 073506 (2006)]. Also it was shown that the increase in the HA plasma potential up to several kilovolts because of the appearance of a noncompensated ion charge in the HA bulk plasma due to electrons fast extraction, leads to explosive emission centers being generated at the HA grid and to nonuniformity in the cross-sectional electron beam current density. Finally, the plasma prefilled mode of diode operation was studied using a simple one-dimensional model of the plasma erosion and the HA plasma electron heating by energetic ions was considered.
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This research was supported in part by US-Israel Binational Science Foundation Grant No. 2006373.