Speaker
Description
Tokamaks such as SPARC or ITER will operate at high fusion performance to achieve energy gains on the order of Q~10. These high performance burning plasmas will generate extreme plasma power exhaust due to the narrowing of the heat flux channel as plasma current increases. In SPARC, for example, the steady state parallel heat fluxes are projected to reach 10 GW/m$^2$. Operating a tokamak safely under such loads is a key challenge for burning plasma machines and fusion power plants. This tutorial introduces the physics of tokamak power exhaust and a suite of codes used to predict the thermal loads onto PFCs.
The HEAT code bridges the gap between plasma power exhaust physics and engineering CAD geometry. HEAT integrates a variety of plasma physics modules including the optical approximation, gyro orbit tracing, ELM filament tracing, runaway electron transport, photon transport, and 3D field heat loads using M3DC1. These physics solvers are coupled to FEM/FVM modules for calculating the PFC temperature, thermal stress, and tungsten recrystallization kinetics.
This tutorial session will guide attendees through descriptions of the physics behind each of the HEAT modules, and practical examples of validation and verification will be provided from across the tokamak fleet.
An analysis of gyro orbit effects will be provided for NSTX-U. Differentiating between SOL transport channels will be demonstrated with results from ASDEX Upgrade. The effects of 3D fields on the heat flux footprint will be discussed for DIII-D. And leveraging the knowledge of power exhaust physics to optimize PFCs for power handling will be
shown for SPARC.