The results of experimental studies of the current and charge balance in the diode unit of the ∈Cyrillic capital letter EpU-500 high-current pulsed electron accelerator (an accelerating voltage of 350-500 keV, a half-height pulse duration of 60 ns, and a total kinetic electron energy of 250 J/pulse) during generation of an electron beam are presented. Planar diodes with multipointed cathodes having diameters of 43-60 mm and manufactured from graphite, copper, and carbon felt were studied. It is shown that the electron-beam divergence in the anode-cathode gap caused by a distortion in the electric field at the periphery of the cathode is the main source of parasitic losses in planar diodes. The half-angle of divergence is 68° at small anode-cathode gaps and decreases to 60° with an increase in the gap. When the diode impedance is matched to the generator's output impedance (at a gap of 10-12 mm), the charge loss is within 12%.
ASJC Scopus subject areas
- Engineering (miscellaneous)