| Article | |
| Title | Isotropic round-wire multifilament cuprate superconductor for generation of magnetic fields above 30 T |
| Author(s) | Larbalestier, D C (Natl. High Mag. Field Lab.) ; Jiang, J (Natl. High Mag. Field Lab.) ; Trociewitz, U P (Natl. High Mag. Field Lab.) ; Kametani, F (Natl. High Mag. Field Lab.) ; Scheuerlein, C (CERN) ; Dalban-Canassy, M (Natl. High Mag. Field Lab.) ; Matras, M (Natl. High Mag. Field Lab.) ; Chen, P (Natl. High Mag. Field Lab.) ; Craig, N C (Natl. High Mag. Field Lab.) ; Lee, P J (Natl. High Mag. Field Lab.) ; Hellstrom, E E (Natl. High Mag. Field Lab.) |
| Publication | 2014 |
| Imprint | 2014-04 |
| Number of pages | 7 |
| In: | Nature Mater. 13 (2014) 375-381 |
| DOI | 10.1038/nmat3887 |
| Subject category | Accelerators and Storage Rings |
| Abstract | Magnets are the principal market for superconductors, but making attractive conductors out of the high-temperature cuprate superconductors (HTSs) has proved difficult because of the presence of high-angle grain boundaries that are generally believed to lower the critical current density, J$_c$. To minimize such grain boundary obstacles, HTS conductors such as REBa$_2$Cu$_3$O$_{7−x}$ and (Bi, Pb)$_2$Sr$_2$Ca$_2$Cu$_3$O$_{10−x}$ are both made as tapes with a high aspect ratio and a large superconducting anisotropy. Here we report that Bi$_2$2Sr$_2$CaCu$_2$O$_{8−x}$ (Bi-2212) can be made in the much more desirable isotropic, round-wire, multifilament form that can be wound or cabled into arbitrary geometries and will be especially valuable for high-field NMR magnets beyond the present 1 GHz proton resonance limit of Nb$_3$Sn technology. An appealing attribute of this Bi-2212 conductor is that, being without macroscopic texture, it contains many high-angle grain boundaries but nevertheless attains a very high J$_c$ of 2,500 A mm$^{−2}$ at 20 T and 4.2 K. The large potential of the conductor has been demonstrated by building a small coil that generated almost 2.6 T in a 31 T background field. This demonstration that grain boundary limits to high J$_c$ can be practically overcome underlines the value of a renewed focus on grain boundary properties in non-ideal geometries. |
Corresponding record in: Inspire
Element opprettet 2015-12-16, sist endret 2017-07-31
