Latest Developments of OLYMPE Platform for Optimizing Design of Fusion Cryomagnetic Systems

In the framework of design studies for large fusion magnets, the development of the OLYMPE multi-physic platform is ongoing at CEA. This platform gathers different solvers and codes for addressing the interdependent analyses required for tokamak superconducting magnet design. The present article focuses on the coupling between conductor design, thermohydraulics, and electromagnetism. The corresponding OLYMPE module aims at producing factors of merit such as the amount of superconducting material, together with major parameters impacting the cryogenic system (operating conditions, thermal loads on the magnet). The Thermo-Hydraulic Design (THD) loop was first developed for TF magnet, considering the most critical conductor and a single burn cycle. The loop is improved by extending the model to coil scale, thus including the whole winding pack, and by considering four burn-dwell cycles so as to reach a periodic behaviour. The case of an EU-DEMO TF magnet design is applied, and the comparison of results before and after THD loop upgrade confirms the validity of first loop version for exploratory studies. The second part of the study focuses on the development of CS magnet design module. The dimensioning process specific to CS results in significant differences with the TF design loop. In particular, the CS design loop requires updating the magnetic field distribution at each design iteration, while the assessment of AC losses thermal load requires defining a scenario for the current in each CS module. Consequently, the CS design process merges electromagnetic and thermohydraulic loops. The workflow is applied to an EU-DEMO CS magnet design.