Divertor biasing on HL-2A is observed to control edge localized modes (ELMs) and modify divertor heat load profiles by generating resonant magnetic perturbations (B-RMPs) via currents driven in the scrape-off layer. In H-mode plasmas, this leads to clear strike-point splitting and significant ELM mitigation. To interpret these results, we perform the first 3D edge transport simulations of such experiments using the EMC3-Eirene code. Toroidal modelling confirms that the magnetic perturbation generated by the divertor biasing current is capable of substantially modifying the edge magnetic topology, resulting in strike point splitting on the divertor target. The plasma transport simulations qualitatively capture the key feature of strike-point splitting observed in the experiment, showing reasonable qualitative agreement with experimental measurements. These combined experimental and modelling results support the physical feasibility of divertor biasing for controlling divertor heat loads and mitigating ELMs in tokamak plasmas, and establish a critical numerical benchmark for this technique.
The effect of resonant magnetic perturbations on the divertor heat and particle fluxes in MAST