AC-Tolerant Multifilament Coated Conductors

TL;DR

This paper demonstrates a method to significantly reduce magnetization losses in multifilament coated conductors, especially coupling losses at high sweep rates, through laser ablation and post-treatment.

Contribution

The study introduces an effective technique to suppress coupling losses in multifilament coated conductors, improving performance at high magnetic sweep rates.

Findings

Hysteresis loss reduced proportionally with filament width.

Coupling loss dramatically decreased and became negligible up to 20 T/s.

Previous conductors showed coupling losses at much lower sweep rates.

Abstract

We report the magnetization losses in an experimental multifilament coated conductor. A 4 mm wide and 10 cm long YBCO coated conductor was subdivided into eight 0.5 mm wide filaments by laser ablation and subjected to post-ablation treatment. As the result, the hysteresis loss was reduced, as expected, in proportion to the width of the filaments. However, the coupling loss was reduced dramatically, and became practically negligible, in the range of a sweep rate up to 20 T/s. This represents a drastic improvement on previous multifilament conductors in which often the coupling losses became equal to the hysteresis loss at a sweep rate as low as 3-4 T/s. These results demonstrate that there is an effective and practical way to suppress coupling losses in coated multifilament conductors.