Center for Advanced Simulation of RF - Plasma - Material Interactions

Robust, reliable, and efficient heating actuators/systems are expected to play a crucial role in future fusion power plants (FPPs). The primary challenge associated with the use of radio-frequency (RF) actuators in all frequency ranges is the interaction with the edge plasma. The conditions of the scrape-off layer (SOL) plasma affect the efficiency of RF heating and current drive. The Center for Advanced Simulation of RF-Plasma-Material Interactions will exercise computation, theory, and experimental verification and validation to deliver high-fidelity RF modeling capabilities and physics understanding in support of this objective. The proposed research will heavily leverage high performance computing resources (HPC) and expertise in mathematics and scientific computing provided by the Office of Advanced Scientific Computing Research (ASCR) researchers, as well as software capabilities for scalable computing developed under the FASTMath SciDAC Institute, the Exascale Computing Project (ECP), and other ASCR-supported projects. These ASCR capabilities will be a fundamental component of this integrated research effort.

A comprehensive suite of high-fidelity simulation tools will be developed that integrate RF-material interactions, realistic antenna structure and first-wall components, and RF wave physics across different regions. This includes examining relevant phenomena such as RF-sheath wall erosion, impurity production and transport, and RF wave propagation and power deposition in the scrape-off layer, plasma edge, and hot core regions. Our tools will comprise both high-fidelity and reduced RF and material models with varying levels of physics fidelity, including machine learning-based models, that can be integrated into a community Whole Facility Model (WFM).

This research will also extend and generalize a hierarchy of RF tool capabilities to non-tokamak configurations. We will consider several fusion plasma configurations that are viewed in the community as leading candidates for an FPP – a tokamak, stellarator, and mirror machine. The physics basis of each FPP configuration drives unique RF actuator requirements. For different magnetic configurations, we will examine the optimal choice of a RF actuator as well as different antenna concepts, and antenna placement. These will be enabled by the use of a modern framework for the coupling of multi-physics packages that are needed in a WFM.