Secondary electron beam loading

Beam loading plays an important part in the determination of the power gain and efficiency of klystrons; hence it is desirable to have an accurate theoretical knowledge of this phenomenon. The usual beam loading analysis considers only the loading effects of a d-c beam of primary electrons on a resonator. It can be shown that these electrons effectively change the shunt impedance of the resonator and shift its resonant frequency¹. However, if this magnitude of this effect is subject to investigation in a resonator with grids, it is found that observed beam loading is many times more severe than primary theory predicts^2,3.