On the use of fluxmetric methods for characterizing feebly magnetic materials

The problems related to the use of a split-coil permeameter for measuring the magnetic properties of materials with low relative permeability are faced. In particular, a challenging problem arises from the series production of steel tapes: magnetic and paramagnetic materials, in fact, exhibit different magnetic properties according to the production process (i.e. annealing and cold work). Consequently, samples of this material differently treated have to be characterized in order to find the optimal cold work and annealing able to minimize raising of magnetism. In this paper, fluxmetric methods, widely employed for magnets testing, are extended to the characterization of feebly magnetic materials. A case study for the series production of steel tapes about co-wound 1.430 stainless steel tapes, the material used for the quench detection in ITER TF coils [1], is presented.