Development and Applications of Magnet Module for SYCOMORE CEA System Code

In the framework of prospective activities for a demonstration power plant, DEMO will be the next step for fusion energy following ITER tokamak. Some of the key design top-level questions can be addressed using macroscopic system-level codes. Those system codes aim to model the whole fusion plant with all its subsystems and identify the impact of their interactions on the design choices. The code SYstem COde for MOdelling REactors (SYCOMORE) is a modular system code developed to address key questions relevant to the tokamak fusion reactor design by giving a global view of technology and physic domains. Among all components, SYCOMORE provides a representation of the magnet system, which is of importance regarding some factor of merits, e.g., fusion power or cost. SYCOMORE is ultimately coupled with an optimizer, scanning a high number of operation configurations and ranking them along selected merits. This scanning requires fast computation for each scanned point, so the magnets modeling must meet a tradeoff between simplicity and accuracy. In this paper, we describe that the way toroidal field (TF), central solenoid (CS), and poloidal field (PF) systems modeling in SYCOMORE was chosen taking into consideration the driving design criteria used in usual magnet design method (temperature margin, copper maximum temperature during quench, mechanical resilience in stainless steel structural parts, etc). The specificities of the reduced magnet representation chosen approach will be exposed, and the benchmarking of the simplified model of the two main systems (TF and CS) applied on DEMO reactor configuration will be compared with the output of a more sophisticated design method using an elaborated tool (CEA design tool) that is used to establish the CEA design of DEMO magnets. Together with this benchmark, a discussion on the limits of this approach will be conducted. PF system implementation being in an early stage, the winding pack design module will be exposed (with its associated benchmarking part with CEA design tool), but not the part of PF current reconstruction with respect to system features. Parametric explorations of DEMO configurations will be reported along different conceptual choices related to the magnets (e.g., superconductor material and performances, and structure resilience limits), and the impact on the magnet system main design features will be exposed. Main lines of the future development work will also be presented.