Abstract of TRINGS2 Project

In preparation for ITER and to promote the early realization of fusion as an energy source, it will be fundamental to understand the effect of plasma turbulence on confinement. Recent advances have made feasible the gyrokinetic simulation of turbulence with realistic geometry and physics. The TRINITY code takes advantage of the scale separation between turbulence and transport by running independent turbulence simulations in local flux tubes at a number of radial locations across the plasma, averaging the turbulence over an intermediate scale, and then incorporating the averages into a large-scale transport simulation. The flux tube simulations may be performed by the GS2 gyrokinetic code, in a combination known as TRINITY-GS2.

We propose to enhance TRINITY-GS2, which currently uses the same number of processors for each flux tube across the plasma, with a load balancing algorithm that allows different numbers of processors to be used for each flux tube, and to be reallocated dynamically based on convergence. In order to enable such reallocation, work already started to change the format of the GS2 restart file will be completed.