High Intensity Muon Beam Facilities with FFAG

We present the PRISM project in Japan to construct a dedicated muon beam facility with high intensity, high purity and high luminosity, based on FFAG (fixed field alternating gradient synchrotron) technology. The main purpose of the PRISM project is to search for an exotic process of charged lepton mixing, in particular a muon-to-electron conversion process. High luminosity, namely narrow energy spread, can be achieved by phase rotation in the PRISM FFAG ring. The PRISM FFAG ring is now under construction at Osaka University. The design and the construction status of the PRISM FFAG ring are presented.