The heat flux control of the divertor plate via strike-point splitting generated by biased targets was proposed in the Headphones HL-2A tokamak (Cui et al 2021 Fusion Eng.Des.173 112963).To understand the helical scrape-off layer (SOL) currents driven by hybrid biasing, two SOL current models (model A and B) are employed.Model A is a simplified 2D model that focuses on investigating the effect of biasing on the sheath and elucidating the fundamental physical mechanism of bias-driven SOL current paths.
The potential, charge density, electric field and current densities are calculated.Model B takes into account the actual tokamak geometry and computes the resonant magnetic perturbations (RMPs) generated by bias-driven Jumper linear decay currents.Additionally, strike-point splitting is observed in the HL-2A tokamak, indicating that the SOL currents generated by hybrid biasing are capable of generating strong RMPs and consequently influence the magnetic topology.These results confirm the potential of heat/particle flux control by hybrid divertor biased targets.