  One of the key systems of a Muon Collider (MC) - seen as the most exciting
option for the energy frontier machine in the post-LHC era - is its interaction
region (IR). Designs of its optics, magnets and machine-detector interface are
strongly interlaced and iterative. As a result of recent comprehensive studies,
consistent solutions for the 1.5-TeV c.o.m. MC IR have been found and are
described here. To provide the required momentum acceptance, dynamic aperture
and chromaticity, an innovative approach was used for the IR optics. Conceptual
designs of large-aperture high-field dipole and high-gradient quadrupole
magnets based on Nb3Sn superconductor were developed and analyzed in terms of
the operating margin, field quality, mechanics, coil cooling and quench
protection. Shadow masks in the interconnect regions and liners inside the
magnets are used to mitigate the unprecedented dynamic heat deposition due to
muon decays (~0.5 kW/m). It is shown that an appropriately designed
machine-detector interface (MDI) with sophisticated shielding in the detector
has a potential to substantially suppress the background rates in the MC
detector.
