The RFOFO Ionization Cooling Ring for Muons
  Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second US Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such \textit{real-world} effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49. 
R. Palmer, V. Balbekov, J.S. Berg, S. Bracker, L. Cremaldi, R.C.   Fernow, J.C. Gallardo, R. Godang, G. Hanson, A. Klier, D....