Heavy impurities, such as tungsten (W) accumulating in the confined plasma core of tokamaks are detrimental to their performance and can lead to plasma disruptions due to radiative collapses. W in the large tokamak ITER is predicted to have strong outward neoclassical transport in the H-mode pedestal which decreases its penetration into the plasma core. However, repetitive instabilities, called Edge Localized Modes (ELMs), must be suppressed to prevent unacceptable heat fluxes to the divertor walls and this has an impact on W transport. ELM-suppression by means of Resonant Magnetic Perturbations (RMPs) degrades the pedestal gradients and gives rise to a 3D plasma response. Studies for present experiments, which have W accumulation in the pedestal, show that the use of RMPs can decrease W core content (e.g. Zhang et al 2024 Nucl. Mater. Energy41 101822). However, it is currently unknown how exactly RMPs change impurity transport in ITER and, in particular, whether the predicted impurity screening can be maintained under such conditions. In this paper, we investigate two ITER 15 MA Q = 10 ELM-suppressed H-mode scenarios with applied 3D fields with RMP current at 60 kAt, with the non-linear hybrid kinetic-extended MHD code JOREK. We show that the driving mechanisms of neoclassical impurity transport become complex and 3D in nature. On top of the MHD solution, we simulate tungsten test-particles with the kinetic Particle-in-Fourier model, including the E-field, all charge states, and collisions including the thermal and friction force. This W transport study includes the impact of vortices that can form in the pedestal region in response to the RMPs. We show that, even including collisional neoclassical impurity transport in conditions leading to an outwards advection, W can be transported from outside the unperturbed separatrix to the top of the pedestal by the vortices. When vortices are not present during RMP application, the outwards neoclassical transport is no longer counteracted. This will potentially lead to an altered optimization criterium for ELM suppression where not only the pedestal should be optimized to maintain neoclassical screening impurities, but the E-field response should be optimized to limit inwards transport through the pedestal. Tungsten mostly enters the core at the top of the plasma due to the vortices, showing that the localization of the tungsten source and transport is important.
Resonant magnetic perturbation effects on pedestal structure and ELMs