Ka-Band High-Power Phase Shifter for High-Gradient Accelerator R&D

The decision to base the next linear electron-positron collider on superconducting radio frequency (RF) technology, with a nominal accelerating gradient of about 30 MeV/m, has renewed the effort to develop working gradients of about 150 MeV/m in warm accelerating structures. However, this high-gradient goal will require the testing of higher frequency RF sources than in the past. To satisy this testing requirement, this project will develop an RF phase shifter for use with a pulse compressor. The phase shifter will be capable of reliably transmitting 100 ns, cm-wavelength pulses of 100-200 MW. In Phase I, two versions of a Ka-band high-power phase shifter will be built and tested at low-power: one version will have a fast-triggered electron beam detuning a resonator, and the other will have an array of gas discharge tubes in resonator grooves in a mirror. The two versions will compared, and the best-performing version selected for engineering development, fabrication, and testing during Phase II. Commercial Applications And Other Benefits as described by the Applicant: The technology should provide a new option for pulse compression to reach higher peak power levels than with presently available components, broadening the range of users that can conduct high-power accelerator R&D. If a future multi-TeV collider were to be driven by external RF sources and pulse compressors, these specialized phase shifters could be required in very large numbers, representing a potential market of millions of dollars.