Three-dimensional edge transport simulations for DIII-D plasmas with resonant magnetic perturbations

The impact of resonant magnetic perturbations on plasma edge transport at DIII-D is investigated with the EMC3-EIRENE code. The code includes a self-consistent fluid treatment of particle, parallel momentum and energy transport for the plasma as well as recycling and kinetic neutral particle transport. It is shown that the magnetic field structure is reflected in the plasma structure as well, both in the patterns of particle and heat loads on the divertor target and in a 3D spatial modulation of plasma parameter in the X-point region and near the midplane on the high field side. In particular, a very strong, toroidally and poloidally localized increase in electron density and temperature outside the separatrix is found. The presented findings of target loads are consistent with earlier 3D heat transport modelling results at DIII-D, but not with heat flux measurements, while reasonable agreement is found for the particle flux. The poloidal modulations introduced by short magnetic flux tubes are consistent with observations and 3D modelling results at TEXTOR and we demonstrate that even for this rather simple flux tube geometry it is necessary to include the full 3D plasma and neutral transport.