Abstract:

Modern tokamaks and future burning plasma experiments exhibit the resonant destabilization of Alfvenic eigenmodes due to the presence of a minority of non-thermal fast particles. Such eigenmodes are able to impact the fast ion confinement, degrading performance and causing possible vessel damage. Stability predictions rely on computationally demanding nonlinear solutions of the Fokker-Plank equation or similar counterparts from gyrokinetics. However, a perturbative treatment from the theory of nonlinear Landau damping has proven very useful on tokamaks and captures much of the relevant physics. Some recent examples and ongoing work will be presented.