Magnetic and Mechanical Design of the Large Aperture HTS Superconducting Dipoles for the Accelerator Ring of the Muon Collider

To further explore the physics beyond the capabilities of the LHC and its High-Luminosity Upgrade (HL-LHC), particle physicists are studying advanced accelerators in order to perform finer measurements and/or reach higher energies. Upon the recommendation of the Updated European Strategy for Particle Physics (ESPP), an International Muon Collider Collaboration has been established to investigate the feasibility of a muon collider facility with a center-of-mass energy of 10 TeV. This endeavor is confronted with several technical challenges, primarily arising from the brief muon lifetime at rest, which is only 2.2 μs. Addressing this stringent constraint necessitates the deployment of innovative technologies, including challengingmagnets, RF systems, targets, shielding, and cooling methodologies. This paper focuses on optimizing the electromagnetic and mechanical aspects of high-temperature superconducting (HTS) dipoles with large rectangular aperture for the accelerator ring, with a bore field up to 10 T, using finite element techniques. The objectives include ensuring a precise control over magnetic field uniformity and a preliminary evaluation of the mechanical behaviour of the HTS coils. The study is aligned with the priority set by ESPP on technological advancements, notably in high-field superconducting magnets, crucial components for any forthcoming circular collider.