Progress of REBCO Coated Conductor Program at SJTU and SSTC

Abstract

At Shanghai Jiao Tong University (SJTU), REBa2Cu3O7‐σ (REBCO) coated conductor (CC) research program started in 2007. With the support of China's First National Key Project on CC Program, SJTU successfully developed hundred meters long class CC tapes with over 300 A/cm (at 77 K, self-field) based on PLD (pulsed laser deposition)/RABiTS processes in 2011. To develop high-performance CC tapes, in 2012, we switched from RABiTS to ion beam-assisted deposition (IBAD)-MgO tape and a pilot PLD/IBAD process CC fabrication line was set up at Shanghai Superconductor Technology Corporation in 2013, and deposition processes were successfully transferred from lab to fabrication line. Under optimized conditions, the IBAD-MgO layers showed pure (001) orientation and excellent in-plane texture. Atomic force microscopy observation showed MgO layer had very smooth surface. The rms is less than 1 nm. On the textured MgO layer, single CeO2 layer showed pure (001) orientation and excellent in-plane texture of ${\text{4}}^{\circ}$ – ${\text{5}}^\circ$ . Reel-to-reel PLD process was already scaled up to >100 m/h tape speed. Kilometer (Km) long CC tapes with over 300 A/cm have been routinely fabricated. Recently, our research work focused on introducing high-density nanoscale artificial flux pinning centers into REBCO superconducting layer to improve in-field superconducting properties and further expand application areas of REBCO tapes.