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 hcoil ≈ 7m. The ratio of the radial field to the toroidal field is of the order 10−4. The ITER- like plasma (Ip=14 MA, Bt=5.2 T) is assumed to be elongated (ε = 1.8) and D-shaped (δ = 0.3). Due to the large acoil it can be shown by Fourier analysis that with a moderate current of 80 kA the coils produce a B1,1 Fourier component of ≈ 10G at the plasma edge. Because of the large distance between the coils and the plasma edge the B4,1 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