Particle simulation of tokamak plasma edge

Abstract

Understanding the plasma turbulence is of major importance for success of ITER, which is in turn the most important step in the development of fusion energy. ELMFIRE is a full particle distribution gyrokinetic simulation code developed to study the dynamics of turbulence and its influence on plasma global behaviour. ELMFIRE can be used, and has already been used, to understand the physics underlying the formation and development of plasma turbulence and its undesirable effects on plasma confinement.

Of particular importance in the study of plasma confinement is the transition between L and H states, referring to Low and High confinement states. Understanding the way to induce an L-H transition in a plasma would lead to an immediate increase of plasma confinement applicable to different plasma devices. The DECI resources obtained for this year have supported ELMFIRE simulations with more memory-efficient code version (extending the calculations into the SOL region) for longer (and heavier) simulations to collisional time scale. Further understanding of pedestal transport and its control has been acquired. The diagnostics of turbulent structures has been improved by correlation studies done for Textor parameters. Confinement transitions have been seen in Tuman-3 configuration by letting the plasma to be heated in the simulations. These findings and learning are proposed to be used for searching for the confinement transition in the Asdex Upgrade edge with ELMFIRE and supported by its sister code ASCOT.