Analysis of ion back-flow in an electron gun of a C-band space TWT

Summary form only given. The synthesis and analysis of a Pierce-type electron gun has been developed from first principles to design the gun of a C-band, 60 W (CW) space TWT. The design of the gun includes an ion barrier anode A₀, kept at a positive potential with respect to the ground anode A₁, to prevent ions from flowing towards the cathode and to reduce ion bombardment at the cathode and hence enhance the life and reliability of the gun. Encouragingly, the space TWT actually developed that incorporates the electron gun designed by the authors has met all the desired specifications.