Structure of picosecond electron beam inside vacuum diode

The structure of the picosecond (∼ 150 ps) electron beam into the cathode-anode interval of the vacuum diode is determined. The electron beam is considered as plane quasiparticles with definite charge density, which follow one by another after the equal periods of time. It is shown that the expansion of concentric layer of the beam under the action of the proper electric and magnetic fields depends significantly on the beam current. The experimental confirmation of calculated estimations is illustrated by recording the electron beam structure on the anode by means of the film sensitive to electron radiation