Assessment of error field from ferromagnetic surrounding of ITER tokamak: ferromagnetic rebar of tokamak complex building

Abstract

Error fields produced by the ferromagnetic rebar of the building of the ITER tokamak complex have been studied. It is shown that the ‘3-mode’ error field produced by the global asymmetry of the building is about 2×10−6 of the toroidal magnetic field. Analysis of error fields caused by local asymmetry of the ferromagnetic elements was performed for the one nearest to the tokamak ferromagnetic structure, bioshield. It was shown that the bioshield produces an error field less than 10−5 of the toroidal magnetic field. Such error fields are acceptable.