Tape Field Emission Electron-Optical System for Terahertz TWT

In this work the field gun structure with ribbon electron beam and the electron-optical system (EOS) based on it are proposed and calculated for terahertz traveling wave tube (TWT) with large current. The thin, wide and long plate of the cathode, lying in the plane of the beam, emits perpendicular to it in both directions and then the beam rotates on 90 degrees and becomes flat. The electrostatic focusing in the form of electrostatic screens and the possibility of magnetic focusing is considered. The emission comes from nanosized film of diamond-graphite clusters deposited on the surface of the cathode, on which the drawing grid are deposited. Analytical and numerical calculation shows the possibility of beam rotation and formation of a ribbon beam.