The Field Emission Array Cathode and Its Application in Traveling Wave Tubes

This paper describes the field emission array (FEA) cathode manufacturing to obtain high current density, the electron gun structure, the fabrication process and the test results of a FEA-gun. A three-dimensional electromagnetic simulation program MAFIA was used to design the FEA electron gun, and the electron beam trajectory was simulated under initial condition of emitted electrons with half angle of 30 degrees. In fabrication of the electron gun, many welding processes were used. The fabricated electron gun was tested in a vacuum chamber with a pressure of 5times10-6 Pa. The field emission array cathode is used as an electron source in a micro-traveling wave tube (TWT)