Fluctuation Spectra and Anomalous Heating in Magnetized Plasma Turbulence

Predicting and controlling turbulent transport are among the most important and

challenging scientific issues facing the International Thermonuclear Experimental

Reactor (ITER) project. Three topics that address the need to understand nonlinear

plasma dynamics and self-organization in complex tokamak geometry are:

Cascades and Propagation in Collisionless Trapped Electron Mode (CTEM)

Turbulence, Turbulent Transport of Toroidal Momentum and the Origins of Intrinsic

Rotation, and Global Kinetic Simulation of Toroidal Alfven Instability. All three topics

are exceedingly challenging, require multi-scale, non-local processes of turbulence

self-organization, and address problems which are highly relevant to ITER.

Nonlinear simulations using a gyrokinetic toroidal code (GTC) for tokamak core, and

another gyrokinetic particle-in-cell code (XGC) for tokamak edge, will address these

important scientific issues and cross-benchmark. The predictive capability of the

GTC and XGC dynamical models will be validated by comparing simulation results

with the largest fusion experiments in the U.S. (DIII-D, ALCATOR C-MOD, and

NSTX tokamaks). These simulations will advance the frontier of computational

sciences in the areas of data management, statistical analysis, and advanced

visualization.