Scaling FFAG rings for rapid acceleration of muon beams

The acceleration of intense and high-energy muon beams is one of the challenge of future neutrino factories. The acceleration of such beams using the synchrotron motion inside stationary rf buckets of scaling fixed field alternating gradient (FFAG) rings is considered in this paper. Possible parameters of a 3.6–12.6 GeV muon ring using 200 MHz rf cavities is presented. Detailed particle tracking simulations are used to demonstrate the large 6D acceptance as well as the relatively good tolerance to errors of this scheme. The improvement of the current neutrino factory baseline scenario, using this type of FFAG ring, is finally discussed.