A model-based strike point sweeping technique applied to JET

In this paper, we present a model-based strike point sweeping technique applied to JET, based on a singular value decomposition of a suitable static matrix of the CREATE_L linearized model, linking gaps to active currents. By doing so, it is possible to find a combination of current perturbations in the active coils inside the vessel able to move the strike points without significantly affecting the overall plasma shape. This allows, in principle, a spread of the divertor heat load with almost no interference with other control systems.The generality of the proposed approach is widely discussed, showing (via simulations) that the method is very effective for a rather large range of JET plasma configurations, and does not seem to be significantly influenced by currents induced in passive structures.The proposed technique has also been successfully validated experimentally on two different configurations, showing the reliability and viability of the method.