  Muon storage rings have been proposed for use as sources of intense
high-energy neutrino beams and as the basis for muon colliders. Phase-space
compression (cooling) of the muon beam prior to acceleration and storage is
needed to optimise performance and cost. Traditional techniques cannot be
employed to cool the beam because of decay during the short muon lifetime.
Ionisation cooling, a process in which the muon beam is passed through an
alternating series of liquid-hydrogen absorbers and accelerating RF-cavities,
is the technique proposed to cool the muon beam. An international collaboration
has been formed to carry out the Muon Ionisation Cooling Experiment (MICE), and
its proposal to Rutherford Appleton Laboratory (RAL) has been approved. The
status of the MICE cooling channel, the instrumentation, and the implementation
at RAL are described, together with the predicted performance of the channel
and the measurements that will be made.
