München 2019 – wissenschaftliches Programm
P 18.127: Poster
Donnerstag, 21. März 2019, 16:30–18:30, Foyer Audimax
Gyrokinetic investigation of the nonlinear dynamics of Alfvénic instabilities and comparison with observations in ASDEX Upgrade — •Francesco Vannini — MPI for Plasma Physics, 85748 Garching, Germany
Shear Alfvén waves (SAW) are perpendicular incompressible waves which propagate along the magnetic field lines in magnetized plasmas. Their velocity is of the same order of magnitude of the typical velocity of energetic particles (EP), which are present in Tokamaks as product of fusion reactions or of heating mechanisms. Consequently, Alfvén modes can resonate with EP and become unstable. In the present poster, Alfvén modes are investigated with numerical simulations with the global particle-in-cell gyrokinetic code ORB5. The dependence of the dispersion relation on the finite electron mass is studied, as well as the phase mixing and the continuum damping. As a main result, the experimental magnetic equilibrium and plasma profiles are considered from a shot of ASDEX Upgrade, and the frequency of the Alfvén modes investigated with ORB5 are compared with the experimental observations.