The PRISM Working Group Members

We, the PRISM working group, would like to express our interest to construct a muon beam facility of the highest beam brightness in the world, based on a novel technique of phase rotation. The facility is called PRISM. PRISM stands for Phase Rotated Intense Slow Muon source. It would provide a muon beam having an intensity of about 10 − 1012μ±/sec, a narrow momentum width of a few %, and no pion contamination. The aimed beam intensity is about four orders of magnitude higher than the highest presently available. The energy of the PRISM beam is relatively low (20 MeV in kinetic energy), since it is aimed to be used for stopped muon experiments in general. For particle physics interest, in particular, an experimental search for lepton flavor violating μ− − e− conversion with PRISM is being planned. The PRISM-II is another muon source with its momentum of around 500 MeV/c and high muon polarization. It would provide a beam for an experimental search for the muon electric dipole moment (EDM). And it could serve, in future, as the first ring for a neutrino factory. PRISM and PRISM-II will use a pulsed proton beam from the J-PARC 50 GeV proton synchrotron (50 GeV PS) by fast extraction. Experimental apparatus and PRISM/PRISM-II will be placed at a proposed pulsed proton beam facility, which is not included in the Phase I plan of J-PARC. Some special arrangement to prevent soil activation at the potential beam extraction port to the facility is requested.