Ballistic analysis of a two-cavity finite beam klystron

Bunching in a two-cavity klystron in the presence of space charge is computed using a disk model of the electron stream. This digital computer study shows that space charge can actually enhance bunching under proper conditions. Optimum bunching distance is discussed along with the details of the effect of space charge on the velocity spread within the beam. The results are synthesized to provide a qualitative picture of the manner in which bunching, velocity spread, and circuit efficiency contribute to efficiency of energy conversion at an output gap.