Both components 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
absorber, 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 housing
four 201.25-MHz RF cavities whose irises are closed with 42-cm diameter thin Be
windows. To contain the muon beam, each RFCC module also has a 1.4-m diameter
superconducting coupling solenoid surrounding the cavities. Both types of magnet
are cooled with multiple 2-stage cryo-coolers, each delivering 1.5 W of cooling
at 4 K.  
Designs for all components are complete and fabrication is under way.
Descriptions of the various components, design requirements, and construction
status will be described.