A variable high-power multi-beam klystron design

We describe here a 1.497 GHz multi-beam klystron with up to 13 kW of continuous output power, greater than 60% efficiency, and stable linear operation at ∼10% below saturation, whose design is based on direct extrapolation from klystrons operating in our electron accelerators. The beam perveance is individually adjusted with a zero-current control-electrode gun to match the parameters of a specific application, such as superconducting accelerating structures. The 18 beams are guided through six toroidal cavities, five operating at the fundamental and one at the 2nd harmonic, by a reverse periodic permanent magnet focusing system.