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Publication Citation: Influence of Ti and Ta doping on the irreversible strain limit of ternary Nb3Sn superconducting wires made by the restacked-rod process

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Author(s): Najib Cheggour; Loren F. Goodrich; Theodore C. Stauffer; Jolene D. Splett; Xifeng Lu; A. K. Ghosh; G. Ambrosio;
Title: Influence of Ti and Ta doping on the irreversible strain limit of ternary Nb3Sn superconducting wires made by the restacked-rod process
Published: April 01, 2010
Abstract: Nb3Sn superconducting wires made with restacked-rod process (RRP®) were found to have a dramatically improved resilience to axial tensile strain when alloyed with Ti as compared to Ta. Whereas Ta-alloyed Nb3Sn in RRP wires showed permanent damage to its current-carrying capacity (Ic) when tensioned beyond an intrinsic strain as small as 0.04 %, Ti-doped Nb3Sn in RRP strands exhibit a remarkable reversibility up to a tensile strain of about 0.25 %, thus making Ti-doped RRP wires more suitable for high-field magnets used in particle accelerators and nuclear magnetic resonance applications where mechanical forces are intense. A strain cycling experiment at room temperature caused a significant drop of Ic in Ta-alloyed wires, but induced an increase of Ic in the case of Ti-doped strands. Whereas either Ti or Ta doping yields a similar enhancement of the upper critical field of Nb3Sn, the much improved mechanical behavior of Ti-alloyed wires clearly makes Ti a better choice over Ta, at least for the RRP wire processing technique.
Citation: Superconductor Science and Technology
Volume: 23
Pages: 4 pp.
Keywords: Superconductors;Ternary Nb3Sn;Alloys;Strain;Irreversible Strain Limit;Strain Cycling;Fracture
Research Areas: Physics, Materials Science, Measurements
PDF version: PDF Document Click here to retrieve PDF version of paper (470KB)