Abstract : The international Muon Ionization Cooling Experiment (MICE), site
d at Rutherford Appleton Laboratory in the UK, aims to build and test one ce
ll of a a realistic ionization cooling channel lattice. This comprises three
 Absorber-Focus-Coil (AFC) modules and two RF-Coupling-Coil (RFCC) modules. 
Both are technically challenging.  
The Focus Coils are dual-coil superconducting solenoids, in close proximity,
 wound on a common mandrel. Each pair of coils is run in series, but can be 
configured with the coil polarities in the same (solenoid mode) or opposite 
(gradient mode). At the center of each FC there is a 20-L liquid-hydrogen ab
sorber, operating at about 14 K, to serve as the energy loss medium for the 
ionization cooling process.  
The longitudinal beam momentum is restored in the RFCC modules, each of whic
h houses four 201.25-MHz RF cavities whose irises are closed with 42-cm diam
eter thin Be windows. To contain the muon beam, each RFCC module also has a 
1.4-m diameter superconducting coupling solenoid surrounding the cavities. B
oth types of magnet are cooled with multiple 2-stage cryo-coolers, each deli
vering 1.5 W of cooling at 4 K.  
Designs for all components are complete and fabrication is under way. Descri
ptions of
the various components, design requirements, and construction status will be
 described.