Pulsed Focusing Recirculating Linacs for Muon Acceleration

Neutrino Factories and Muon Colliders require the rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses International Linear Collider (ILC) RF structures can provide the exceptionally fast acceleration needed to enable each muon to pass several times through each high-gradient cavity. However, the technical feasibility, ultimate limitations, and cost effectiveness of such schemes have not been fully determined. This project will develop technology to rapidly change the strength of the RLA focusing quadrupoles as the muons gain energy. This strategy will increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. In Phase I, a single-linac RLA that incorporates pulsed focusing quadrupoles will be designed at 1.3 GHz for intended use with ILC-type SRF accelerating structures. Technical solutions for fast pulsed quadrupoles and droplet arc magnets will be investigated to determine feasibility and potential cost savings. Commercial Applications and other Benefits as described by the awardee: Future large scale facilities such as Neutrino Factories and Muon Colliders would benefit from more effective use of RF cavities by having RLA designs with more recirculation passes. Cost savings should follow from the value of the reused RF relative to the cost of the droplet arcs