High-current electron beams with a current density of up to 100 A/cm2 generated by a plasma-cathode gas-filled diode at low accelerating voltages are studied. Two types of gas discharges are used to produce plasma in the cathode. With glow and arc discharges, beam currents of up to 150 A and 400 A, respectively, have been obtained at an accelerating voltage of 16 kV and at a pressure of 1–3·10−2 Pa in the acceleration gap. The ions resulting from ionization of gas molecules by electrons of the beam neutralize the beam charge. The charge-neutralized electron beam almost without losses is transported over a distance of 30 cm in a drift channel which is in the axial magnetic field induced by Helmholtz coils. The results of calculations for the motion of electrons of the charge-neutralized beam with and without axial external field are presented and compared with those of experiments.

The effect of the intensification of electron emission in a plasma-cathode diode with a grid-stabilized plasma boundary has been investigated. For a pulsed (100-μs) electron beam of 15-20-keV energy that passes through the plasma formed as a result of gas ionization by an electron beam, it has been revealed that an increase in pressure increases the emission current at a fixed plasma-cathode discharge current, and the emission current can become greater in magnitude than the discharge current. It has been shown that a significant increase in electron-beam current is provided by the secondary ion-electron emission that results from the bombardment of the emission electrode surface by the accelerated ions coming from the boundary of the anode plasma.Index Terms-Electron beam, plasma cathode.

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