Abstract
Reduction of ac losses in applied ac fields can be accomplished through either the creation
of filaments and bridging in YBCO coated conductors or an assembly of narrow width
YBCO tapes. The ac losses for each of these geometries were measured at 77 K in
perpendicular ac fields up to 100 mT. While ac loss reduction was achieved with YBCO
filaments created through laser scribing and inkjet deposition, the assembly of stacked
YBCO conductor provides an alternative method of ac loss reduction. When compared to a
4-mm wide YBCO coated conductor with a critical current of 60 A, the ac loss in a stack of
2-mm wide YBCO coated conductors with a similar total critical current was reduced.
While the reduction in ac loss in a 2-mm wide stack coincided with the reduction in the
engineering current density of the conductor, further reduction of ac loss was obtained
through the splicing of the 2-mm wide tapes with low resistance solders. To better
determine the practicality of these methods from a stability point of view, a numerical
analysis was carried out to determine the influence of bridging and splicing on stability of a
YBCO coated conductor for both liquid nitrogen-cooled and conduction cooled geometries.
