Adaptive Simulation of Cold Plasma in RF Heaters

Accurate RF simulations of fusion energy systems require the definition of high-fidelity analysis geometries. The steps in the RF simulation workflow include defeaturing of antenna CAD models; combining antenna, reactor wall and physics components into an analysis model geometry; applying physics attributes to the model; automatically generating a graded mesh; and executing an adaptive finite element analysis that includes the application of a-posteriori error estimation, and mesh adaptation. The simulation workflow employs modeling and meshing tools from Simmetrix, the high-order PetraM+MFEM analysis platform from PPPL+LLNL, and curved mesh adaptation procedures from RPI. The poster will overview the simulation workflow components. This will include discussion of technical developments required to support the coarse curved mesh generation and curved mesh adaptation needed to support the effective use of high-order adaptive RF simulations. The advantages of using high-order finite element methods for resolving wave fields for geometrically complicated strap type antenna in tokamak fusion systems will be discussed. This will include a study of the right combination of mesh adaptation and element-order that is most effective to obtain results to the desired level of accuracy.