First experimental observations of the ferromagnetic shielding effect in
high-Tc superconducting coated conductors were carried out. Experimental
results were compared to simulations calling upon finite-element calculations
based on the H-formulation of Maxwell equations to model superconducting strips
with ferromagnetic shields. Samples of copper-stabilized coated conductors were
electroplated with nickel shields and afterwards characterized. Both externally
applied oscillating transverse magnetic fields as well as transport currents
were studied. Having observed promising gains with respect to the reduction of
ac losses in both cases, we further investigated the potential of ferromagnetic
shielding. The numerical model was able to reproduce and also predict
experimental results very well and will serve as an indispensable tool to
determine the potential of soft ferromagnetic materials to significantly reduce
hysteretic losses.Comment: 4 pages, 3 figures, 1 tabl
