Concept of a Hybrid (Normal and Superconducting) Bending Magnet based on Iron Magnetization for 80-100km Lepton/Hadron Colliders

We present a concept of twin aperture iron dominated bending magnets. These compact “transmission line” dipoles are meant to be installed in the same 80-100 km tunnel of the Future Circular Colliders (FCC) currently being studied at CERN, where they shall be used for the high energy injector synchrotrons. The main feature is the coupling of a resistive cable (for first use in a leptons machine) with a superconducting one (for hadrons operation, presumably in a second phase of FCC). The main challenges in terms of operating field range are commented in the light of similar magnets already built.