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Description
This work presents a numerical modeling framework for quench protection in the non-planar superconducting magnets of the GIGA stellarator reactor (Gauss Fusion), which store energies on the order of 100 GJ. The study focuses on the development and application of a predictive multi-physics model for an innovative active protection concept that eliminates external dump resistors by using the structural steel plates of the winding pack as distributed resistive elements for energy dissipation. The approach is based on an integrated simulation model coupling the THEA code, specialized in one-dimensional thermo-electro-hydraulic modeling of superconducting cables, with a dedicated electrical circuit model. The THEA component resolves the transient behaviour of the conductor in both LTS (Nb₃Sn) and HTS (REBCO) configurations, including quench initiation and front propagation, helium coolant dynamics, and current redistribution. The circuit model represents the current paths through the steel plates and evaluates their electro-thermal response. The model simulates quench initiation mechanisms through localized thermal disturbances and critical current degradation, as well as detection logic based on voltage and temperature thresholds. Following protection triggering, the coupled model captures the transient transfer of current from the superconductor to the resistive steel plates and the associated Joule dissipation of magnetic energy. A systematic parametric study is performed using the model to assess sensitivity to geometric, thermal, and electrical design parameters, interfacial insulation properties, conductor characteristics, and quench detection strategies. The simulation results demonstrate the capability of the model to predict autonomous protection performance, hot-spot temperature suppression, and low-voltage operation, providing quantitative guidance for the design of simplified cryogenic and power system architectures.
