Modification of scrape-off layer transport and turbulence by non-axisymmetric magnetic perturbations in ASDEX Upgrade

A brief survey of the status of ELM mitigation by non-axisymmetric magnetic perturbations in ASDEX Upgrade is presented. ELM mitigation occurs for a wide range of parameters when the peripheral plasma density is above a density threshold. The focus of this paper is on the influence of magnetic perturbations on scrape-off layer transport and turbulence in L- and H-mode discharges. In low density L-mode strike-line splitting in the divertor as footprint of the 3D magnetic topology with magnetic perturbations is well visible in the heat flux density profiles. At enhanced densities strike-line splitting cannot be observed, transport masks the 3D substructure and the flattening of the density profile around the separatrix causing an enhanced SOL density vanishes. In H-mode strike-line splitting occurs before the ELMs are mitigated. With magnetic perturbation the SOL cross-field transport rises, with ELM mitigation onset intermittency increases.