Progress in production and performance of second generation (2G) HTS wire for practical applications

Rare earth (RE) based second generation (2G) high temperature superconducting (HTS) wires with critical current I
_c
(77K, self-field) of 300 ~ 500 A/cm-w and piece lengths of a few hundred meters are now being routinely produced. Results from past and ongoing demonstration projects using the 2G HTS wires suggest that the practical application of this new material is appealing, promising and challenging. In this paper, the most important properties of the commercial-grade 2G HTS wires are discussed.