The effect of NTMs and TAEs on fast particles in ITER

Introduction Fast particles, such as fusion-born alphas and energetic ions from external heating, are important in ITER for two primary reasons: 1) They are responsible for self-sustained heating and current drive. 2) They constitute a significant energy source in the plasma and, therefore, pose a potential risk to the material structures. In this work we study how magnetohydrodynamic (MHD) instabilities affect the fast particle distribution in a realistic ITER magnetic configuration including the toroidal field (TF) ripple, test blanket modules for tritium breeding (TBMs) and ferritic inserts (FIs). The perturbations in the magnetic vector potential and scalar electric potential caused by the MHD modes were used to derive valid guiding-center equations of motion in a general coordinate system [1]. Using these equations, it is possible to trace particles with the MHD modes using any desired form of the magnetic field, while earlier methods were either restricted to use static MHD modes or axisymmetric magnetic fields. The following ITER scenarios are considered: 1) Fusion alpha simulation in the presence of NTMs in the standard 15 MA H-mode scenario, 2) fusion alpha simulation in the presence of TAEs in the advanced reversed shear 9 MA scenario and 3) the same for NBIs. In all the cases, the effect of MHD modes on fast ion power loads to the wall and on plasma heating is studied. Moreover, in case of NBIs, the effect of MHD modes on the current driven by the beams is investigated.