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An experimental result of operation of a high-current hollow mode (HA) with a BaTi ferroelastic plasma source (FPS) incorporated in it is discussed. Generation and characterization of a high-current electron beam with current amplitude of ~1.2 kA was achieved under an accelerating pulse amplitude less than or equal to 300 kV and ~400 ns pulse duration.

Parameters of a hollow-cathode electron source and the general electron beam are presented. The parameters were studied for different discharge current amplitudes and anode grid cell sizes.

We describe the operation of a hollow-anode electron source with a biased output grid in a diode powered by a 200 kV 400 ns pulse. The hollow anode had a ferroelectric plasma source incorporated in it. Three electrical schemes for the hollow-anode output grid bias were tested and compared. It is shown that the use of an autobias grid allows electron-beam generation with a current amplitude up to 1.2 kA in a plasma emission-limited mode and with insignificant plasma prefilling of the accelerating gap. The use of an externally biased output grid (either with a positive or negative potential) showed the possibility to control the emission properties of the hollow-anode plasma without changing the amplitude of the discharge current. Electron beams with an amplitude up to 2 kA and insignificant plasma prefilling of the accelerating gap were obtained. It was found that the application of the accelerating pulse leads to a drastic increase in the potential of the plasma up to several kV. It is shown that, in spite of the large positive plasma potential, electron emission occurs due to the dynamics of ions inside the sheath near the hollow-anode grid. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The time- and space-resolved laser induced fluorescence diagnostics approach is employed to analyze the performance of a ferroelectric plasma source-assisted hollow anode (HA) electron source present in a vacuum diode. The presence of an accelerating pulse is shown to lead to a significant enhancement in the plasma ion temperature of the system.

The detailed experimental research results of the multicapillary dielectric cathode (MCDC) assisted by either a velvet-type igniter or ferroelectric plasma sources (FPS) are presented. The glass multicapillary cathodes with less surface erosion assisted by a FPS show longer lifetime and better vacuum compatibility compared to multicapillary cathodes assisted by a velvet-type igniter.

An attempt is made to investigate the properties of the plasma and the electron beam produced by velvet cathodes in a diode powered by a ~200kV, ~300 ns pulse. It is shown that the interaction of the electron beam with the stainless-steel anode does not lead to the formation of anode plasma.

Spectroscopic measurements are reported of the plasma formed inside a hollow anode (HA) with a ferroelectric plasma source (FPS) incorporated in it. The HA was used as a cathode in a dioxide supplied by an accelerating pulse and it was found that the HA discharge is accompanied by the formation of a dense plasma layer at the surface of the FPS.

Operation of a hollow plasma anode (HPA) with a hollow cathode incorporated in it for the production of preliminary plasma is studies with the help of discharge in current amplitude up to 1 kA. Results showed gaseous discharge without formation of plasma spots at the anode wall and the output grid.

High current electron beam generation is studied in a diode using the hollow plasma anode (HPA) as an electron source. The plasma parameters inside the HPA were measured for different N2 and Xe gas pressures and discharge current amplitudes is described.

The nature of the electron emission from the metal-ceramic cathode, the parameters of the electron diode and the generated electron beam versus different amplitudes of the accelerating voltage and different anode-cathode gaps are investigated. The results show that the uniformity of the generated electron beam depends strongly on the duration of the accelerating pulse.

Thomson scattering and visible spectroscopy were applied to study the parameters of plasma formed in a hollow-anode discharge (about 1 kA) prior and during electron beam extraction (approximately 1 kA; 300 kV). The discharge was ignited and sustained by ferroelectric plasma sources incorporated in the hollow anode. It was found that during the hollow-anode operation the density and energy of the ferroelectric surface plasma electrons are about 1015 cm-3 and not more than 5 eV, respectively. The density and temperature of the bulk hollow anode plasma electrons were found to be about 6×1013 cm-3 and about 10 eV, respectively. During an acceleration pulse the surface plasma electron density and energy increased to approximately 6×1016 cm-3 and not more than 20 eV respectively, while the bulk plasma parameters remain unchanged. Also, it was shown that the plasma formation on the ferroelectric surface is accompanied by the generation of microparticles having velocities up to 3×105 cm s-1. [ABSTRACT FROM AUTHOR]

We report results on the generation of a large-cross-section (about 170 cm 2 ) 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 10 12 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. [ABSTRACT FROM AUTHOR]