Design of a high power three-cavity gyroklystron system

Summary form only given. A 30-MW gyroklystron amplifier is being designed to demonstrate the feasibility of this type of device as a driver for future 1 -TeV linear colliders. The system uses a beam produced by a magnetron injection gun. The system is designed to yield a 500-kV, 200-A, 1-μs beam with α=1.5 and low velocity spread. To achieve the necessary gain, a system with three or more cavities must be used. The experimental effort has focused on characterizing the beam with air core transformers, 90°-sector capacitive probes, diamagnetic loops, and a B-dot probe. A TE₀₁₁ two-cavity device has been built and tested. This has made it possible to study the start oscillation current and to test the design codes on a relatively simple system. Three codes have been used to design the three-cavity system: (1) a nonlinear particle code, (2) a cavity and whole circuit code, and (3) a start oscillation current code. These codes make it possible to design not only the microwave circuit but also the loading to suppress oscillation in unwanted modes