Updates on the Preliminary Electromagnetic and Mechanical Design of the Block-Coil Dipole for the Muon Collider Ring

Within the framework of the International Muon Collider Collaboration (IMCC), a feasibility study is underway for a 10 km collider ring aiming to achieve 10 TeV of center-of-mass energy. The short muon lifetime (2.2 μs at rest) imposes stringent requirements on the magnets, which must be compact, high-field, and large aperture to both maximize luminosity and host the internal shielding for the muon decay products. These challenges point to the use of REBCO High-Temperature Superconductors (HTS) and motivate the development of innovative design strategies addressing electromagnetic performance, quench protection, AC losses and mechanical integrity. This work presents an updated 2D analysis of dipoles in a block-coil configuration for the muon collider ring, featuring an innovative stacked-cable orientation with a novel end-winding concept. An improved electromagnetic design with a bore field of 16 T in a 140 mm aperture diameter is introduced, accompanied by an analytical estimation of hysteretic losses, which now accounts also for transport current effects. In addition, an advancement of the preliminary mechanical design is provided through Finite Element Method (FEM) using ANSYS software, employing a stress-management strategy to mitigate the high Lorentz forces.