The Tracker Systems for the Muon Ionization Cooling Experiment

The Muon Ionization Cooling Experiment (MICE) will be the first experiment to demonstrate muon

ionization cooling in the momentum range of 140 MeV/c < p? < 240 MeV/c. The experiment is a single-

particle experiment where the input and output beam emittances are made from an ensemble of

selected single-muon candidates. The two fiber trackers in a solenoidal field of 4T (one before and

one after the cooling channel) measure the muon 4-momenta and provide the basic information for

determining the emittances. This paper gives a brief overview of MICE and then describes the details

of the fiber tracker assemblies, their unique construction technique (which for the first time used 350

?m diameter scintillating fiber), the readout electronics and performance with respect to light yield,

hit resolution and tracking efficiency as measured in a recent cosmic-ray test of the two final tracker

systems.