Assessment of error field from solitary ferromagnetic elements located outside of ITER tokamak

Abstract

The error fields produced by localized steel objects in the ITER tokamak building have been studied in this paper. The critical mass of the objects, producing in the plasma region the ‘3-mode’ error field of 0.1 Unit (10−6 of the toroidal magnetic field), is estimated for a set of object positions. It is shown that the critical mass is scaled with distance as R 7, if R≥30 m.