Transport AC Loss Reduction in Striated YBCO Coated Conductors by Magnetic Screening

It is known from our previous work that magnetic screening is an effective way of decoupling the strands in striated YBCO coated conductors. Different configurations of multifilament geometry with filaments embedded in ferromagnetic materials of different thickness and different magnetic permeability have been modeled in the past and a reduction of transport ac loss predicted by FEM calculations. In the present work we propose a much simpler and more practical method for magnetic decoupling of the strands in YBCO coated conductors. This method consists in filling just the inter-filamentary space between the filaments by a ferromagnetic material, rather than embedding the filaments completely. Calculations of transport ac loss reduction were performed using a finite element method. A comparison of the loss reduction of this new geometry with previous results (assuming filaments completely surrounded by ferromagnetic material) as well as the case of perfect screening were made. Due to the "flat" (nearly 2D) geometry of striated YBCO coated conductors the present method gives almost the same transport ac loss reduction as completely embedding the filaments in a ferromagnetic material.