Plasma Control Studies Using DIII-D Design Tools in Support of ITER

Control analysis and design tools developed at DIII-D [1] have been applied to ITER in studies supporting design of the ITER Plasma Control System (PCS) [2] to prepare for the upcoming PCS Preliminary Design Review (PDR). These studies include assessment of an extremum-seeking approach to real-time error field correction, advances in vertical controllability metrics, simulation of plasma initiation, and development of an integrated algorithmic approach to exception handling toward disruption-free operation of ITER. Integrated simulations have demonstrated the robustness and mutual compatibility of key control algorithms, as well as the potential of critical exception handling algorithms for limiting the disruption frequency in ITER. The present studies follow the ITER PCS Preliminary Design focus on control requirements for the First Plasma and PreFusion Plasma Operations (H/He species) operating phases of ITER. Selected control scenarios are studied in several phases of the plasma discharge, including plasma startup, rampup, rampdown, and asynchronous response to off-normal or fault conditions. These studies confirm the existence and consistency of control solutions with both device resources and PCS architecture.