A Design Tool for Predicting Parasitic Oscillations in High-Power Sheet-Beam Klystrons

High-power klystrons are expensive critical components of proposed high-energy particle accelerators such as the International Linear Collider. Spurious oscillations in traditional pencil-beam klystrons have been a major cause of poor performance and tube failure, requiring expensive retrofitting to correct. Although sheet-beam klystrons have recently been proposed as a less expensive and more robust alternative to conventional pencil-beam devices, they also are subject to problems associated with spurious oscillations.. Unfortunately, there is presently no analysis tool that can predict spurious oscillations in klystrons, and this shortcoming has significantly contributed to very long and expensive development cycles for these devices. This project will create an analysis software module that will perform a virtual beam transmisson test in a klystron model. This test will excite any spurious oscillations that can arise from noise on the beam, and these modes will then be identified and characterized by the software. Phase I will focus on the klystron circuit, and create prototype software that will extract all eigenmodes in the circuit in a specified frequency band. The required integrations will then be performed along particle tracks obtained via the simplifying assumption of a confined drifting beam. The prototype software will be integrated into a module that will be hosted by a commercial analysis product, and the capability will be validated against previously established analytic and numerical results. Commercial Applications And Other Benefits as described by the Applicant: More robust designs for very high-power klystrons should help reduce the construction and operation costs for high-energy particle colliders used by the physics community. Klystrons and other microwave tubes are also used in a variety of commercial and military applications, including microwave telecommunications, radar, remote sensing, industrial heating/drying, and commercial accelerators for medical and other purposes