• M. Apollonio
  Imperial College of Science and Technology, Department of Physics, London
• A.P. Blondel
  DPNC, Genève
• D.J. Kelliher
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon

Monitoring the muon beam properties in the final stage of the Neutrino Factory (the Decay Ring) is important for the understanding of the beam itself and a crucial piece of information for the downstream physics detectors. The main topics to be assessed are: knowledge of the muon beam energy, divergence of the muon beam and muon beam current. In the framework of the International Design Study for the Neutrino Factory (IDS-NF) a Race Track model Decay Ring based on G4beamline has been produced to understand how electrons from muon decays can be used to infer the energy properties of the beam via the spin depolarisation technique. The use of other codes, like Zgoubi, to generate a realistic beam including effects like spin polarisation, are considered. A general discussion on the remaining topics is presented.