Development of plasma control schemes and plan of plasma physics studies in JT-60SA

The main mission of JT-60SA project is to contribute to early realization of fusion energy by conducting supportive and complementary works for ITER towards DEMO reactor. This paper summarized the main results of preparatory studies on JT-60SA for the contributions to ITER on plasma physics including the first ITER campaigns. In advance to the integrated commissioning, the plasma shape control method based on an advanced scheme of ISO-FLUX equilibrium control has been developed and implemented in the JT-60SA equilibrium controller. The Adaptive Voltage Allocation (AVA) scheme automatically optimizes the control gains for the plasma position and shape. Plasma breakdown scenarios in JT-60SA have been investigated by a new method based on the optimization of inversely reconstructed magnetic fluxes, ECH assistance, and estimation of the start-up region without generating runaway electrons. During the initial research phase I, the stable operation at high current in large superconducting machine and the ITER risk mitigation for non-activated phase will be highlighted. A robust VDE predictor has been developed with machine learning and the adaptive voltage allocation scheme. The control schemes of divertor heat load with impurity seeding has been investigated. The JT-60SA is capable of operating at high triangularity and high elongation, close to ITER plasma. It has been examined by EPED1 model that highly shaped plasma operation of JT-60SA enables the edge pressure gradient to be high against the peeling-ballooning mode and bring a favorable pedestal pressure. The JT-60SA Experiment Team will address the major issues of the plasma physics and control studies in ITER and DEMO-relevant regimes.