Design of a cloverleaf-racetrack dipole demonstrator magnet with dual ReBCO conductor

For future 20+ T accelerator type magnets, ReBCO superconductors are ideal for their high current density in high magnetic field. At CERN, demonstrator dipole magnets using ReBCO conductor are being developed in order to study their feasibility. In this work, a design of a cloverleaf-racetrack magnet is presented, which consist of two poles. A key problem in such magnets is how to realize the coil-ends without causing degradation due to coil winding, cool down and operation. The cloverleaf geometry accommodates the particle beam pipe without any hard-way ReBCO tape bending. To design such geometry of the coil-end, a new method using Bézier splines is presented. The ReBCO coils are wound with dual tape conductor where the ReBCO layers are facing each other. For quench protection, the coils are non-insulated, allowing the coil current at quench to redistribute transversally through the winding pack. A comparison between dry-wound and soldered non-insulated coils is made. Progress on the electromagnetic and mechanical design of the cloverleaf magnet is reported in this paper.