Design of a Sheet Beam Electron Gun for 850GHz Staggered Double Vane Traveling Wave Tube

A sheet beam electron gun for 850GHz staggered double vane TWT is designed in this paper. The designed beam achieves a beam current of 20mA, beam voltage of 28.1kV and cross-sectional dimension of
$\pmb{0.12}\mathbf{mm}\pmb{\times 0.03}\mathbf{mm}$
. And the beam transmission efficiency with a designed uniform permanent magnetic field is achieved with 95.7%. Finally the beam-wave interaction with above parameters is calculated and the output power is obtained with 33.8mW.