Experimental validation of HEAT on ASDEX Upgrade in support of SPARC

The HEAT code predicts the thermal energy transported from the plasma to the surrounding 3D plasma facing component (PFC) structures. HEAT has been used to design the SPARC PFCs, and will be used in the SPARC interpulse workflows for physics model validation and machine protection. In order to validate SPARC power exhaust workflows that will be used during operations, an offline workflow has been developed and applied on ASDEX Upgrade (AUG). AUG is similar to SPARC in many aspects due to a full tungsten first wall, a comparable machine size and powerful auxiliary heating systems. In this work, both the optical heat flux and photon volume emission modules of HEAT are experimentally validated using high-powered H-mode AUG pulse data. The diagnostic suite for these pulses includes IR thermography, thermocouples and calorimetry. HEAT predictions for both heat flux and temperature are compared to the diagnostic data and presented. AUG is capable of accounting for 93% of the exhausted energy in H-mode using an energy balance algorithm. Combining the energy balance algorithm with HEAT constrains the fraction of power in various transport channels such as convection, conduction, and radiation. Building upon the existing AUG energy balance algorithms, a new open source interpulse workflow for SPARC is being developed and validated at AUG. The new algorithm will run between pulses in less than 10 minutes, and provides a flexible interface to new diagnostics. Plans for this new energy balance workflow will also be presented.