Electromagnetic analysis of the twin loops structure for the control of the vertical instability in NET/ITER fusion reactor

The problem of the vertical instability of the plasma column in the NET/ITER (International Thermonuclear Experimental Reactor) reactor is analyzed via a suitable low-frequency electromagnetic modeling of the structure. For this purpose a 3-D eddy current code is coupled with techniques belonging to MHD (magnetohydrodynamics) and control theory domains. In particular, the specific design concept called twin loops, which has recently been proposed for the passive control of the plasma vertical instability in NET/ITER, is analyzed. The results show good agreement among models of different natures adopted to solve this kind of coupled problem