Adapting Trinity for Use in Stellarator Plasma Profile Predictions*

The complexity of transport in high-temperature magnetized plasma used in fusion devices is due to particle fluctuations caused by turbulent effects including drifts, instabilities, and impurities. The complex origin of the turbulence effects and the magnitude of scales they traverse in time and space makes it difficult to correctly model the plasma profiles.

Trinity is a program that was written to simulate equilibrium profiles in tokamaks by solving a transport equation for individual tube-shaped volumes. It is relatively simple to find a steady-state solution for each tube, and a full profile can be built by coupling them. The flux tube model accounts for a large percentage of the fluctuations found in a tokamak and gives a reasonable profile estimate.

Trinity was originally written in Fortran and designed for use with tokamaks. The goal of this project is to bring Trinity over to Python making it more user-friendly, while integrating Trinity with other programs such as VMEC, GX, and GS2 for more accurate turbulence estimates, and finally, adapting Trinity for stellarator profiles. With these changes, Trinity will be capable of producing highly accurate stellarator plasma profile predictions, which would assist the design of stellarators with reduced turbulent transport