Phase Pushing Studies of a Fundamental-Mode, Eight-Beam, Four-Cavity Multiple-Beam Klystron

In this paper, we presented the results of experimental measurements of rf phase as a function of cathode voltage for an eight-beam, four-cavity MBK that operates at a center frequency of 3.25 GHz. The phase pushing factor was measured in both the small- and large-signal regimes of the MBK´s operation. The experiment was also modeled using a simple analytic theory that assumes a constant velocity for beam electrons and a more sophisticated numerical model TESLA.