Quantitative correlation between the void morphology of niobium-tin wires and their irreversible critical current degradation upon mechanical loading
| Autor: | Carmine Senatore, Christian Barth, Ciro Calzolaio, Alexander Rack, Yuhu Zhai, Bernd Seeber, Davide Matera |
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| Přispěvatelé: | Department of Quantum Matter Physics, University of Geneva, Group of Applied Physics [Geneva] (GAP), University of Geneva [Switzerland], European Synchrotron Radiation Facility (ESRF), Princeton Plasma Physics Laboratory (PPPL), Princeton University |
| Rok vydání: | 2018 |
| Předmět: |
STRAIN
Void (astronomy) Fabrication Materials science lcsh:Medicine ddc:500.2 NB3SN CONDUCTORS PORE 01 natural sciences Article PORE STRUCTURE chemistry.chemical_compound PORE ANALYSIS Hot isostatic pressing 0103 physical sciences KIRKENDALL VOIDS SUPERCONDUCTING MATERIALS FIELD IMAGE ANALYSIS Composite material Niobium-tin lcsh:Science 010306 general physics Electrical conductor Stress concentration [PHYS]Physics [physics] 010302 applied physics Superconductivity Multidisciplinary lcsh:R SUPERCONDUCTING STRUCTURE PERFORMANCE chemistry 13. Climate action Magnet MICROTOMOGRAPHY lcsh:Q CONDUCTOR DEVELOPMENT |
| Zdroj: | Scientific Reports, Vol 8, Iss 1, Pp 1-13 (2018) Scientific Reports 'Scientific Reports ', vol: 8, pages: 6589-1-6589-13 (2018) Scientific Reports, Nature Publishing Group, 2018, 8, pp.6589-1-6589-13. ⟨10.1038/s41598-018-24966-z⟩ Scientific Reports, Vol. 8, No 6589 (2018) |
| ISSN: | 2045-2322 |
| Popis: | Understanding the critical current performance variation of Nb3Sn superconducting wires under mechanical loading is a crucial issue for the design of next generation accelerator and fusion magnets. In these applications, the mechanical properties of the conductors may become a limiting factor due to the strong electro-magnetic forces resulting from the combination of large magnets and intense magnetic fields. In particular, the presence of voids in the superconducting filament structure, which are formed during the fabrication and the reaction heat treatment, determines localized stress concentrations and possibly the formation of cracks. In this work, we demonstrate a quantitative correlation between the void morphology and the electro-mechanical limits measured on different Bronze route Nb3Sn wires. Hot Isostatic Pressing (HIP) prior to the reaction heat treatment is utilized to partially eliminate the voids. The wires’ void distributions - with and without HIP treatment - are detected and statistically analyzed using high energy X-ray micro tomography. The stress concentration due to the shape and distribution of the voids as well as their impact on the electro-mechanical properties are determined through finite element method modeling. Finally, the results are quantitatively correlated with the experimentally determined limits of the irreversible critical current degradation upon mechanical loading. |
| Databáze: | OpenAIRE |
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