Model based estimation of the Eddy currents for the ITER tokamak

Eddy currents flowing in the conductive structures surrounding the plasma in a tokamak affect magnetic measurements (magnetic fields and fluxes at given points), which are used to estimate plasma quantities such as plasma toroidal current, position and shape. Due to their spatial distribution and their fast variations, eddy currents are difficult sources to characterize. This is particularly true when magnetic sensors are outside the conductive plasma chamber implying that eddy currents flow between the so-called measurement contour and the plasma region. As a matter of fact many plasma shape identification algorithms assume the plasma current distribution as the only magnetic source located inside the measurement contour. In this paper we deal with the problem of estimating eddy currents in the ITER tokamak by means of a dynamic observer to wash out their contribution to magnetic measurements. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence