Flexible, Axisymmetric MHD Solver for Coupled Plasma and Liquid Metal Dynamics

Blankets are a necessary technology for tritium breeding and cooling in future fusion reactors. However, some blanket concepts, such as liquid lithium and lead-lithium, are highly conductive and may be free to flow within channels, meaning they will directly interact with plasma dynamics via coupled electromagnetic effects. In the process of blanket concept development and pilot plant design, there is a need for simple models that can effectively capture the interplay between the plasma and liquid breeding blanket. An axisymmetric implementation of MUG [1], a component of the Open FUSION Toolkit (OFT) [2], has been developed to solve the visco-resistive compressible MHD equations with high geometric fidelity. MUG is coupled with TokaMaker, a 2D time-dependent plasma equilibrium solver already available in OFT [3], to compute the current distribution and flow profile in the blanket as a result of time-evolving magnetic fields, which then feeds back on the concurrent plasma evolution. The tool is leveraged to study the impact of plasma disruptions on the blanket fluid, as well as if and how the blanket response alters the plasma dynamics.

[1] C. Hansen et. al., 2015 Phys. Plasmas 22 042505

[2] https://github.com/OpenFUSIONToolkit/OpenFUSIONToolkit

[3] C. Hansen et. al. 2024 Comput. Phys. Commun. 298 109111