Beam-ion transport dependence on magnetic perturbations spectrum and plasma helicity in the ASDEX upgrade tokamak

The beam-ion resonant transport in the presence of externally applied magnetic perturbations was characterised in terms of the MP spectrum and the magnetic field q95 using experimental data and full-orbit simulations. Through the variation of the particle Pf, it was observed that q95 affects the beam-ion transport due to a shift of the resonant transport layer. Higher q95 leads to an inward shift that contributes to reducing the beam-losses by displacing the transport layer from the beam ions born at the edge and decreasing the transport intensity as the MP δB amplitude is weaker towards the plasma core. The inclusion of a mixed toroidal spectrum leads to a superposition of the resonances associated to each toroidal mode. This makes it possible to control the intensity of the transport by combining different toroidal spectra and Δφ to minimise the outward transport of beam ions while still mitigating the ELMs. Acknowledgments: This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.