Efficiency enhancement by phase focusing and collector depression

Nonlinear calculations [1], [2], [3] of the el ectron-wave interaction process in TWA’ s, klystrons and BWo’ S have permitted the calculation of interaction efficiencies along with information about the energy state of the spent beam. These calculations have been primarily concerned with the r. f. interaction process and have not considered the effects of collector depression on the overall efficiency of the particular device. In this paper the effect of collector depression on device efficiency is studied theoretically and calculations are presented for the TWA and the BWO under a variety of operating conditions.