  This White Paper brings together our previous studies on a Muon Collider (MC)
and presents a design concept of the 6 TeV MC optics, the superconducting (SC)
magnets, and a preliminary analysis of the protection system to reduce magnet
radiation loads as well as particle backgrounds in the detector. The SC magnets
and detector protection considerations impose strict limitations on the lattice
choice, hence the design of the collider optics, magnets and Machine Detector
Interface (MDI) are closely intertwined. As a first approximation we use the
Interaction Region (IR) design with beta-star=3 mm, whereas for the arcs we
re-scale the arc cell design of the 3 TeV MC. Traditional cos-theta coil
geometry and Nb3Sn superconductor were used to provide field maps for the
analysis and optimization of the arc lattice and IR design, as well as for
studies of beam dynamics and magnet protection against radiation. The stress
management in the coil will be needed to avoid large degradation or even damage
of the brittle SC coils. In the assumed IR designs, the dipoles close to the
Interaction Point (IP) and tungsten masks in each IR (to protect magnets) help
reducing background particle fluxes in the detector by a substantial factor.
The tungsten nozzles in the 6 to 600 cm region from the IP, assisted by the
detector solenoid field, trap most of the decay electrons created close to the
IP as well as most of the incoherent electron-positron pairs generated in the
IP. With sophisticated tungsten, iron, concrete and borated polyethylene
shielding in the MDI region, the total reduction of background loads by more
than three orders of magnitude can be achieved.
