A high performance grid-controlled electron gun

High performance grid-controlled electron gun is the base of modern high power and broadband traveling-wave-tubes. We have developed a shadow grid electron gun, its perveance can be more than 1.6 micro-perveance. The parameters and diagram of the gun is given in this article. Better tactical performance, better anti-interference performance, good mobility are the important conditions for radar to alive. High power traveling-wave-tubes are the key device of the radar; they need high output power, flexible modulation method, and small permanent magnetic focusing system. Accordingly the electron gun of high power TWT should provide high perveance electron beam and should be shadow grid controlled. This article introduces a shadow grid controlled electron gun, the cathode voltage is 26kV, and the perveance can be up to 1.6 micro perveance. The calculated electron trajectories by the 2D compute program are shown. The affect of the circular wires of the shadow grid and the control grid to the moving of the electrons are taken into account during calculation. The shielding factor due to radial grid wires has also been considered.