Modeling of Quench Protection Concepts for Canted-Cosine-Theta Type High-Field Magnets

An innovative high-field superconducting magnet of Canted-Cosine-Theta (CCT) type has been proposed for Future Circular Collider 16 T dipole magnet design. The unique mechanical structure intercepts the accumulated forces lowering the stress on the windings, constituting intrinsic stress management in high-field Nb
₃
Sn accelerator magnets. However, this structure also constitutes a barrier for heat to quickly propagate in case of a quench. To succeed in the CCT-type magnet design and construction, quench protection is a challenging task that requires a detailed investigation of the electrothermal behavior of the magnet. In this paper, the protectability of a two-layer short model CD1 (Canted Dipole) built at PSI is studied using multiphysics simulations. Two protection methods are considered: energy extraction and coupling-loss induced quench. The 2D User-Defined Elements (UDEs) developed at Lawrence Berkeley National Laboratory in ANSYS Parametric Design Language, which support the multi-dependence material properties and include the effect of inter-filament coupling currents, are adapted and used in the coupled electrothermal, electrodynamic and electrical circuits calculations. A first-of-a-kind CCT-type magnet protection study using UDEs is presented. The generic model method will be validated through CD1 cold tests. Furthermore, these studies will prepare the ground for four-layer CCT protection concepts for FCC.