Design, Performance and Cabling Analysis of Nb3Sn Wires for the FCC Study

The hadron collider proposed by the Future Circular Collider (FCC) study would require high-field superconducting magnets capable of producing a dipole field of around 16 T in a 50 mm aperture. To develop a suitable conductor for these magnets, CERN is coordinating a conductor development programme aiming to obtain Nb$_3$Sn wire with a non-copper critical current density of 1500 A mm$^{-2}$ at 16 T and 4.2 K, in lengths suitable for manufacturing 14 m long magnets, and able to withstand cabling without significant degradation. Here we report the superconducting characterisation and quantitative microscopy of recently-developed Nb$_3$Sn wires with novel layouts and compositions, and evaluate their suitability for Rutherford cabling based on cabling trials and rolling studies. An analysis of the influence of wire layout, materials and mechanical characteristics on cabling performance is presented, to support recommendations for future wire designs.