Fast Multi-Harmonic Kickers

The next generation nuclear physics accelerator facility, the Electron Ion Collider EIC), will accelerate and collide spin polarized electrons and ions focused to an unprecedented density at their point of collision. To achieve the desired electron/ion density at the focal point, the technique of electron cooling will be applied. In this technique, the ion beam is temporarily accompanied by a high current electron beam in what is called the “cooling section”. Jlab has designed a multi-pass energy recovery cooler where the electron beam is redirected back to the entrance of the cooling section for multiple passes to increase efficiency. This scheme requires beam-switching kickers to extract and inject the electron beam with speed and precision that is beyond the state of the art. In response to this urgent need, Electrodynamic and Jlab have been working together on a unique solution, fast multi-harmonic kickers. Multi-harmonic kickers use cavities with multiple harmonic modes that are driven by computer controlled multi-harmonic sources to produce fast kicking pulses. Two designs are being simultaneously developed, one for transverse kicking, and the other for longitudinal boosting with magnetic separation. Both development efforts are finally within reach of beam line evaluation; this is the goal of this SBIR. The purpose of this SBIR is to experimentally evaluate both potential fast kicking solutions on Jlabs UITF beamline Upgrade Injector Test Facility). Both of these solutions will deliver intra-bunch fast kicks by simultaneously superimposing multiple RF frequencies within a harmonic cavity. Electrodynamic and Jlab have established a solid foundation for this goal. At the time of this submission, both cavity designs have been physically prototyped, both have had computer controlled multi-harmonic sources developed for them, and vacuum compatible prototypes are planned to be constructed during the Phase I period. Remaining is the development of high power RF amplifiers for each harmonic and high power harmonic power combiners to deliver the kicking pulse. Phase I will develop high power amplifiers and harmonic combiners to drive the kickers, and will support the fabrication and construction of vacuum compatible kicker cavities. The Phase II project will result in the experimental evaluation of both these technologies at Jlab’s UITF.