Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 1158569

Final Technical Report. FG02-06ER54881

Lee, Peter·Larbalestier, David
View original source ↗Read source document ↗Export metadata ↓

Abstract

For over 25 years the Applied Superconductivity Center has been integral to the successful development of superconductors for magnetic confinement fusion reactors, culminating in being a part of the “dream team” assembled by the ITER Organization to address the failure of prototype ITER cable-in-conduit conductors to pass testing in the SULTAN facility, an issue that if not addressed successfully would have limited the useful lifetime of the reactor. While being called on through the years to address the immediate needs of facility construction we also continued fundamental studies of fusion applicable superconductors so that magnet designers could make use of improved performance, reliability and cost. The annual Low Temperature Superconductors workshops, jointly organized with LBNL, became the most important meeting for dissemination of data between university laboratories, national laboratories and industry.

Explore related subjects

221236 MATERIALS SCIENCE70 PLASMA PHYSICS AND FUSION TECHNOLOGY75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYBulk SuperconductorsCable-in-Conduit-ConductorsImage AnalysisMicrochemical AnalysisNb3SnREBCOSuperconducting WiresSuperconductors

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Lee, Peter, Larbalestier, David. 2014-09-26. Final Technical Report. FG02-06ER54881. https://doi.org/10.2172/1158569

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2023

ac susceptibility studies of intra- and intergrain properties of high-$J_c$ Bi-2212 wires

Bi 2 Sr 2 CaCu 2 O x (Bi-2212) is the only high-$T_c$ superconductor (HTS) available as a multifilamentary round wire with multiple architectures and it is a very promising conductor for the realization of high-field applications. Despite their relatively simple wire fabrication by the powder-in-tube technique, Bi-2212 wires require a tightly controlled overpressure heat treatment (HT) with a multi-parameter time-temperature schedule to achieve high critical current density, $J_c$. Further, the variation of these HT parameters, changes in the wire design, wire diameter and powder quality can lead to variations in both the microstructure and the superconducting performance. Particularly noticeable are variations in $J_c$ performance and degree of filament bridging. In this work, we focus on the use of different magnetic characterization techniques to estimate the bridging level and assess the balance of INTER-grain and intra-grain superconducting properties including the irreversibility field ($H_{\text{irr}}$) and the pinning energy ($U_0$) in differently processed wires. Regardless of the actual bridging level, we find that the supercurrent flows at the filament bundle level, not just at the individual filament level. Moreover, using AC susceptibility we identify two distinct supercurrent contributions, one related to the intra-grain and one to the INTER-grain properties, whose irreversibility fields are different but without large sample-to-sample variation. Moreover, an additional component of intra-grain pinning mechanism becomes effective at low temperatures with positive effects also on the INTER-grain performance. The work clearly shows that detailed magnetic characterizations can become valuable tools to investigate the performance of differently processed Bi-2212 wires, correlating their microstructure and overall transport $J_c$, to obtain a deeper understanding of the causes of performance variation and paths to achieve further improvement.

2212↗