Application of JET - Like perturbation coils for ELM - mitigation in ITER

The error field correction coils (EFCC) at JET mounted at a significantly larger distance than e.g. the I-coils in DIIID were effective in ELM suppression. The potential applicability of EFCC-like coils in ITER is investigated here. The investigated coils for n=2 and n=3 are placed at the distance R_coil ≈ 11m from the ITER axis, have a roughly rectangular shape with a side length of a _coil ≈ 18m, the height h_coil ≈ 7m. The ratio of the radial field to the toroidal field is of the order 10^-4. The ITER - like plasma (I_p=14 MA, B_t=5.2 T) is assumed to be elongated (ε =1.8) and D-shaped (δ = 0.3). Due to the large a_coil it can be shown by Fourier analysis that with a moderate current of 80 kA the coils produce a B _1,1 Fourier component of ≈ 10G at the plasma edge. Because of the large distance between the coils and the plasma edge the B_4,1 component is there roughly one order of magnitude smaller. The thickness of the ergodic layer near the x - point, in the transport barrier, is approximately 25 cm.