Power exhaust for potential future ARC reactor concepts is studied, utilising large-scale complex plasma edge simulations codes. Three ARC designs are investigated in this work: CFS’s ARC V2A, as well as Radiative L-mode and Negative-Triangularity ARC concepts. A range of divertor configurations are studied and examined, from standard divertors to advanced divertor magnetic topologies such as the X-point Target and Super-X Divertors. These results of these simulation studies will enable the identification of divertor configurations viable for a realisable fusion reactor.
The power exhaust projected for future tokamak-based fusion reactors presents a major challenge for fusion energy; fusion power plants will need high radiation in the SOL to reduce divertor plasma temperatures/fluxes to levels that project to realistic lifetime PFC erosion rates. The divertor targets – specifically armoured plates where the plasma makes contact with the vessel components – need to have heat fluxes/temperatures kept below key material limits to avoid damage from erosion/melting (and subsequent core contamination). Failure of the divertor components at the reactor level can be equated to failure of the device as a whole. However, the divertor power exhaust problem remains unsolved in the fusion community.
The divertor design for ARC is still an open question. Both the vacuum vessel and the divertor designs are intended to remain flexible for as long as possible, so that the results of advanced divertors experiments can inform the final design of ARC. Many potential designs could be considered for an ARC-class device, including different operational modes (H-, I- and L-mode) as well as negative triangularity concepts. Divertor simulations provide the ability to explore different divertor designs and identify the requirements for successful power exhaust in a realisable ARC fusion reactor.
Large-scale edge plasma simulation codes such as SOLPS-ITER and SOLEDGE2D are utilized for this work.
