Status of mice, the international muon ionization cooling experiment*

Muon ionization cooling provides the only practical solution to prepare high-brilliance beams necessary for a Neutrino Factory or Muon Collider. The Muon Ionization Cooling Experiment (MICE) is thus a strategic R&D project for future muon facilities. It is under development at the UK’s Rutherford Appleton Laboratory. It comprises a dedicated beam-line to generate a range of input emittance and momentum, with time-of-flight (TOF) and Cherenkov detectors to ensure a pure muon beam. Emittance will be measured in a first magnetic spectrometer with a scintillating-fiber tracker. A cooling cell will then follow, alternating energy loss in liquid hydrogen and RF acceleration. A second spectrometer identical to the first one and a particle-identification system will measure the emittance of the outgoing muon beam. In the 2010 run, completed in August, the beam and most detectors have been fully commissioned, and first measurements of input-beam emittance have been performed using the TOF detectors. The staged plan of emittance and emittance-reduction (cooling) measurements that will follow in 2011 and beyond is presented.