Design of magnetic cloak for an alternating magnetic field with multilayer ReBCO insert

Use of superconductors for the shielding of the magnetic field is a common solution nowadays. In case when the magnetic signature of the shielding device matters, forming a magnetic cloak by combining superconductor with ferromagnetic material is a viable option. When considering the operation in alternating magnetic fields the AC loss linked to the delay in phase of the shielding currents represents an important topic. It is well known that the coated conductor (CC) tapes represent a valid alternative to bulk superconducting material when an AC loss reduction appears as a significant requirement. However, the commercially available coated conductors are usually limited to 12 mm width, therefore finding a suitable arrangement of tapes plays a significant role in the magnetic cloak design. We made a set of experiments on two possible arrangements in the superconducting part (helically wound tapes or straight pieces of the tape) and with the total number of layers up to six. For understanding the mechanism of magnetic field penetration inside the cloak the 2D and 3D numerical models were built. Presented numerical models helped in the localization of the cloak component with high energy dissipation. Analysis of the experimental and computation results allow us to formulate some recommendations for the construction of the superconducting part of the magnetic cloak.