An electron diode having a ferroelectric plasma cathode (FPS) controlled by
optic fibers was operated at a repetition rate of 0.5 Hz during 1
hour, when an accelerating pulse of ~250 kV in amplitude and ~250 ns in duration is applied. The application of the fiber optic decoupling
allows easy control and synchronization of the FPS operation with the firing
of the HV generator. It was shown that the use of the FPS with fast fall
time of the driving pulse allows reproducible generation of an electron beam
having a current amplitude of ~1 kA and uniform cross-sectional
current density distribution. It was shown also that in the case of the
driving pulse ringing, the application of the accelerating pulse during the
fall in the negative ringing leads to a plasma pre-filled mode of diode
operation due to intense ion emission from the FPS. When the accelerating
pulse is applied during the rise in the positive driving pulse ringing, one
obtains diode operation with limited plasma emission ability. Only when the
accelerating pulse is applied during the fall in the positive ringing of the
driving pulse does one obtain diode operation in space-charge limited mode.
This dependence of the diode operation on the timing of the accelerating
pulse application with respect to the driving pulse is explained by
processes related to the screening of ferroelectric bounded surface charges
by the plasma charged particles.