On the Effective Modes of Electron Bunches Deceleration in the Gap of the Klystron Output Cavity

The process of deceleration of electron bunches in the klystron output cavity is considered. It is shown that effective deceleration is possible only for a sufficiently narrow bunch. Such bunches are obtained only in the process of COM-bunching. It is shown that the process of deceleration in the output gap involves the formation of a dynamic electron layer, including electrons with zero and negative velocities, which should not go beyond the gap. This requirement leads to the need to increase the output gap. The results of modeling real klystron with a limited length and a relatively high beam perveance, for which the considered effects are significant, are presented.