Speaker
Description
In tokamaks, a strong and stable toroidal magnetic field is essential for plasma confinement. Among the available materials for toroidal field coil, REBCO is a promising candidate due to its excellent stability margin and high critical magnetic field. However, the design and analysis of toroidal field coils, which consist of multiple components such as REBCO-coated conductors, solder, stabilizers, cooling channels, and insulation, pose significant challenges. Many components have very thin dimensions, making them unsuitable for direct meshing in finite element modeling. Furthermore, the significant Lorentz forces and high stress levels in the coils require the inclusion of elastoplastic nonlinear properties in the model. These factors, combined with the geometric complexity, lead to substantial computational costs.
To address these challenges, we developed a multiscale modeling framework. This approach splits the model into a large-scale model and a small-scale model, where the two interact dynamically: the small-scale model provides equivalent material properties to the large-scale model, while the large-scale model supplies boundary conditions to the small-scale model. This method captures detailed mechanical behaviors while maintaining computational efficiency.
In this study, we implemented a finite element model capable of accurately reflecting the mechanical behavior of each component in the toroidal field coil. This model enables a rigorous analysis of coil performance, contributing to the development of mechanically robust and efficient designs for tokamaks, which are critical for advancing fusion technology.
