Donnerstag, 28. Februar, 8:30 Uhr, H 0105
An ab-initio description of turbulent flows in plasmas on large and small spatial scales is provided, respectively, by magnetohydrodynamic and gyroorbit-averaged kinetic (i.e., gyrokinetic) theory. In both cases, a deeper understanding of the underlying phenomena has been fostered by the exponential growth in computer power which now enables direct numerical simulations with reasonably high resolution. In the second case, progress in the areas of algorithm development and mathematical problem formulation have also contributed significantly. As it turns out, while there naturally exist a number of similarities between plasma turbulence and ordinary fluid turbulence, one also finds several fundamental differences which shall be addressed in the talk. Moreover, various (linear) drive and (nonlinear) saturation mechanisms that govern gyrokinetic plasma turbulence will be illustrated by means of intuitive physical pictures and visualizations of simulation data, and their relationship to magnetohydrodynamic turbulence will be discussed. The respective applications range from fusion research to astrophysics to dynamo theory. The overall focus will be on recent advances and future challenges in these areas.
Frank Jenko
Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching