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.

This work presents the experimental and theoretical research of low pressure discharge characteristics in a large sized hollow cathode using treated work pieces. The dependence of discharge voltage on gas pressure and system geometry has been obtained. It is demonstrated that the high plasma homogeneity with concentration up to 1012 cm2 and plasma temperature within the order of 1 eV is obtained. It is shown that the external discharge current enables the independent control of discharge current and its voltage.

This paper presents the theoretical and experimental study of the excitation of electromagnetic waves in the TEM-mode in coaxial vircator with radially divergent electron beam. Excitation of electromagnetic oscillations, emission spectrum, instability increment of electromagnetic oscillations, and formation of a virtual cathode are investigated using the kinetic equation and numerical simulation (PIC code KARAT). It was shown that the resonant interaction of the electron beam is most effectively done with the TEM-mode. The possibility of TEM-mode excitation with its subsequent transformation into TE10-mode of a rectangular waveguide has been experimentally demonstrated.

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