Exploring Hybrid Designs for a 14 T Common Coil Demonstrator Magnet (DAISY)

Building on the initial magnetic design of DAISY, the 14 T common coil magnet demonstrator being developed at CIEMAT under the High Field Magnet (HFM) programme, this paper investigates the feasibility of hybrid designs combining Nb3Sn and NbTi for high- and low-field regions, respectively. The primary goal is to minimise superconductor usage while ensuring that the magnet meets the functional requirements of future collider applications, such as the Future Circular Hadron Collider (FCC-hh). The study examines the potential to achieve accelerator-grade field quality without ancillary coils and to maintain minimal multipole variation between low and nominal currents, highlighting the trade-offs in superconductor efficiency. Comparisons are made with all Nb3Sn designs, including magnet protection, to identify the relative advantages and limitations of hybrid layouts. The results offer valuable insights into optimising superconductor usage and refining design strategies for next-generation high-field common coil magnets, addressing the unique challenges associated with hybrid configurations.