"SPECIAL PLASMA SEMINAR: Nonlinear dynamics of phase-space zonal structures and energetic particle physics in fusion plasmas"

 

 

ABSTRACT:

 

The concept of phase space zonal structures is the natural generalization of phase space holes and clumps, when there is no time scale separation between nonlinear dynamics evolution of phase space structures and the wave-particle trapping time. Their nonlinear evolution is generally non adiabatic and plays a crucial role for resonant particle transport in nonuniform plasmas; e.g., energetic particles in burning fusion plasmas. Here, the interplay between mode structures and energetic particles is an essential ingredient for understanding and interpreting these phenomena. In this work, the general theoretical framework for investigating nonlinear dynamics of phase space zonal structures is introduced and analyzed. Furthermore, theoretical studies and numerical simulation results are presented and compared, showing that frequency chirping and phase locking are the processes by which secular resonant particle transport can occur on meso- and macro-scales.