Design and fabrication of pole-controlled electron gun in PPM

Pulse electron gun is an important part of pulse TWT. The grid-controlled electron gun is not fit for high power pulse TWT and space TWT for its deficiency in stability and long life. Pole-controlled electron gun is a preferable technique. A pole-controlled, hollow-beam electron gun has been successfully designed and fabricated with rigorous calculations and judicious choice of its physical variables. The influence of the electron gun geometry on the hidden variables, including its perveance, its beam waist, and its laminar flow, was evaluated by means of directly measured results and by some theoretical derivation.