Nonlinear wave-particle interactions and phase-space structures

International audience; Wave-particle interaction is a defining paradigm of plasma physics. Nonlinear problems arise in the ITER-relevant context of energetic particle (EP) interaction with Alfvén waves, collisionless trapped electron mode turbulence and transport, trapped ion ITG instabilities, radio-frequency heating and magnetic reconnection. In this paper, we report on fundamental advances in the understanding of nonlinear trapping and its effects on stability, saturation, turbulence and transport. These results have broad implications for EP instabilities, drift-wave turbulence and transport, and many other applications to fusion physics.