Development of a 201 MHz 10 MW Hollow Beam Klystron

The future high energy MUON Collider will require several vacuum amplifers capable of providing multi-megawatts at several different frequencies. The initial acceleration of the cold muons will require a vacuum amplifier capable of generating 10 MW of RF power at a frequency of 201 MHz, a pulse length of 500 microseconds, and a pulse rate frequency of 15 Hz. To achieve these requirements, this project will simulate a novel hollow beam klystron (HBK) employing a space charged limited cathode. In comparison to proposed sheet beam or multiple beam klystrons, this HBK will employ a single cathode with zero beam convergence and an interaction circuit operating at greatly reduced voltage gradients. Phase I will design, analyze and simulate all HBK components, use in-house computer codes to evaluate the actual electrical and mechanical parameters, and determine their performance limiting values. Phase II will finalize the mechanical design, fabricate the required components and subassemblies, and combine all to obtain a hard vacuum high power HBK. Then, the HBK will be tested to the required specifications. Commercial Applications and other Benefits as described by the awardee: A low cost HBK, operating at sufficiently low frequency, would provide RF power to linacs that employ superconducting accelerating cavities. The technology also should form the basis for lower hollow beam devices that can power commercial linacs, generating high intensity X-rays for commercial and medical applications.