Plasma boundary reconstruction in JET by magnetic measurements

The reconstruction of the plasma boundary is a critical issue in the monitoring and control of fusion devices. The problem can be solved by the solution of force balance magneto-hydro-dynamic equations but, unfortunately, the computing burden can be not compatible with the needs of the on-line control. Advanced electromagnetic modelling of the plasma, based on surface equivalent currents recently proposed, can be a compromise between accuracy and promptness especially when a fully 3D treatment is necessary or foreseen. A procedure able to take advantage of the magnetic measurements to provide a plasma boundary reconstruction is here presented. The paper includes the illustration of a first assessment carried out on the JET by using the data of a standard axisymmetric shot, with the aim to check the coherence between the experimental evidence and the numerical procedure.