Overview of Research Results from the SciDAC Partnership for Simulation of Fusion Relevant RF Actuators*

An overview is given of research related to the interaction of ion cyclotron range of frequency (ICRF) power with the tokamak scrape-off layer (SOL) and core. We discuss the development and application of the RF full-wave solver Stix and the more general FEM analysis platform Petra-M, both based on the Modular Finite Element Framework (MFEM), highlighting work on implementation of high-fidelity geometric descriptions of ICRF antennas in the NSTX-U and WEST Tokamaks, incorporation of nonlinear RF sheath boundary conditions, matrix pre-conditioners, and progress on implementation of our RF codes on GPU's. We will review progress on the development of a far-SOL fluid transport solver for equilibrium (the MAPS MFEM mini-app) and the study of RF ponderomotive force effects on the edge / SOL using a combined edge transport and RF solver model (UEDGE and Vorpal). Results for the interaction of RF power with metallic surfaces will be presented, including PIC simulations of the ion energy-angle distributions at ICRH antennas in RF sheaths as well as a description of an integrated workflow for RF impurity generation and transport. Finally, we will report progress on coupled Fokker Planck / full-wave simulations for ICRF using both continuum and particle-based approaches.