Framework for Assessment of Magnetic Equilibrium Controller Performance on the MAST Upgrade Spherical Tokamak
In this work we present the assessment framework for magnetic equilibrium controllers on MAST-U spherical tokamak. Such controllers are essential for MAST-U since exhaust physics and core-edge integration studies require advanced divertor plasma configurations. The developed framework is based on the TokSys suite of plasma control codes, which was adapted and upgraded for MAST-U. However, extra capabilities were added on top of Toksys to support the development of new control algorithms, deployment of controllers to the plasma control system and evaluation of their performance. The controller assessment was realized via closed loop integrated control simulations with the actual MAST-U plasma control system and different physics-based plasma models. Since all components of the assessment chain were experimentally validated, these simulations provide qualified controllers applicable for direct use in the experiment. This resulted in the successful experimental demonstration of the advanced plasma shape control on MAST-U with minimal on machine development time.