Design of a Bow-Tie Shaped 50 GeV Muon Storage Ring

The design of a muon storage ring for a neutrino factory is described. It operates at 50 GeV and has a bowtie shape. It sends neutrino beams from two long straight sections with a small muon beam divergence to two distant detectors at 1000 and 3000 km distance. It is designed for a normalised emittance of about 1.67 mm and an rms momentum spread of 0.5 %. The procedure for arriving at the parameters of the optical modules and of the whole storage ring and their values are given. The verification of the optical design includes tracking many thousands of muons for their lifetime, and demonstrates that the dynamic aperture is larger than the physical one. The parameters of the RF system and of the fast injection kickers are also considered.