High-Performance Bi-2212 Round Wires Made With Recent Powders

• Published in: IEEE transactions on applied superconductivity Vol. 29; no. 5; pp. 1 - 5
• Main Authors: Jiang, Jianyi, Bradford, Griffin, Hossain, S. Imam, Brown, Michael D., Cooper, Jonathan, Miller, Evan, Huang, Yibing, Miao, Hanping, Parrell, Jeff A., White, Marvis, Hunt, Andrew, Sengupta, Suvankar, Revur, Rao, Shen, Tengming, Kametani, Fumitake, Trociewitz, Ulf P., Hellstrom, Eric E., Larbalestier, David C.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.08.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bars; Bi-2212 wire; Bismuth strontium calcium copper oxide; Conductors; Critical current density; Critical current density (superconductivity); Heat treatment; High temperature superconductors; Magnets; NMR; Nuclear magnetic resonance; Overpressure; Powders; superconducting magnet; Superconducting magnets; Superconductor; Wire; Wires; Superconductor; critical current density; superconducting magnet; Bi-2212 wire
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2019.2895197

Multifilamentary Bi 2 Sr 2 CaCu 2 O x (Bi-2212) wire made by the powder-in-tube technique is the only high-temperature superconductor made in the round shape preferred by magnet builders. The critical current density ( J C ) of Bi-2212 round wire was improved significantly by the development of overpressure heat treatment in the past few years. Bi-2212 wire is commercially available in multiple architectures and kilometer-long pieces and is a very promising conductor for very high-field NMR and accelerator magnets. We studied the effects of precursor powder and heat treatment conditions on the superconducting properties and microstructure of recent Bi-2212 wires. Short samples of recent wire with optimized overpressure processing showed J C (4.2 K, 15 T) = 6640 A/mm 2 and J C (4.2 K, 30 T) = 4670 A/mm 2 , which correspond to engineering critical current densities J E (4.2 K, 15 T) = 1320 A/mm 2 and J E (4.2 K, 30 T) = 930 A/mm 2 .