Jiang J, Bradford G, Hossain S I, Brown M, Cooper J, Miller E, Huang Y, Miao H, Parrell J A, White M, Hunt A, Sengupta S, Revur R, Shen T, Kametani F, Trociewitz U P, Hellstrom E E, Larbalestier D C
Applied Superconductivity Center, National High Magnetic Laboratory, Tallahassee, FL 32310, USA and also with Florida State University.
Applied Super-conductivity Center, National High Magnetic Laboratory, Tallahassee, FL 32310, USA and also with Florida State University.
IEEE Trans Appl Supercond. 2019 Aug;29(5). doi: 10.1109/TASC.2019.2895197. Epub 2019 Jan 24.
Multifilamentary BiSrCaCuO (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 ( ) 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 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 (4.2 K, 15 T) = 6640 A/mm and (4.2 K, 30 T) = 4670 A/mm, which correspond to engineering critical current densities (4.2 K, 15 T) = 1320 A/mm and (4.2 K, 30 T) = 930 A/mm.
采用管内粉末技术制造的多丝BiSrCaCuO（Bi-2212）线材是唯一一种制成圆形的高温超导体，这种形状是磁体制造商所青睐的。在过去几年中，通过开发过压热处理技术，Bi-2212圆形线材的临界电流密度（ ）得到了显著提高。Bi-2212线材有多种结构形式且有千米长的产品可供商业采购，是用于非常高场强核磁共振和加速器磁体的极具前景的导体。我们研究了前驱体粉末和热处理条件对近期Bi-2212线材超导性能和微观结构的影响。经过优化过压处理的近期线材短样品显示 （4.2 K，15 T） = 6640 A/mm以及 （4.2 K，30 T） = 4670 A/mm，这分别对应工程临界电流密度 （4.2 K，15 T） = 1320 A/mm和 （4.2 K，30 T） = 930 A/mm。
