Speaker
Description
Iron-based superconductors (IBS), especially 122 type, are very promising candidates for high-field applications because of its ultrahigh Hc2 > 70 T at 20 K, low anisotropy ( < 2 for 122) , and ease of fabrication. Recently, thanks to the great supports from Chinese government, significant progresses on the IBS wires have been made, in terms of both Jc enhancement and practical research. In this talk, the overview of the recent progress will be provided. Firstly, the highest transport Jc values have achieved 0.15 MA/cm^2 (Ic = 437 A) at 4.2 K and 10 T in densified and textured 122 tapes. The transport Jc measured at 4.2 K under high magnetic fields of 27 T is still on the level of 55 kA/cm2. Secondly, in order to reduce costs and improve the mechanical strength, high strength stainless steel/Ag and Cu/Ag 122 composite conductors have been fabricated, with transport Jc above 50 kA/cm^2 in 10 T. For round wires, the highest Jc value reached 31 kA/cm^2 in Cu/Ag composite sheathed wires at 4.2 K and 10 T, obtained by the hot-isostatic-press technology. High-Jc 7-, 37-filament 122 wires were successfully fabricated by the PIT method. Thirdly, based on the experience of high-performance short samples and multifilamentary wires process, high performance 100-m-long multifilamentary superconducting tape has been produced using the scalable rolling process, confirming the great potential for large-scale manufacture. Finally, the latest results of the first joint between 122 IBS superconducting wires will be presented.
