Investigation of a density modulated electron beam emitted by a ferroelectric plasma cathode

Abstract

We present experimental results of the generation of a high-frequency modulated electron beam in a diode with a ferroelectric plasma cathode. The energy of electrons in the modulated beam is significantly higher than that obtained in previous experiments, reaching 150 keV. The maximum amplitude of the modulated beam current reaches 65 A, which corresponds to a beam power of 4.5 MW. Data concerning the influence of the diode geometry and the accelerating voltage on the electron energy and the amplitude of the modulated beam current are presented. It was found that the beam modulation is caused by the variation of the beam electron density, and that it has uniform cross-sectional electron beam current density distribution. Efficient transport of the modulated electron beam in a guiding external magnetic field without distortion of its waveform is demonstrated. The electron beam modulated at 190 MHz with an amplitude of 25 A was transported in the magnetic field (0.3–3 kG) along a distance of 50 cm. In addition, it was shown that the modulated beam could be efficiently transported through a slow wave structure without the application of the external magnetic field.