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Deformation Behavior and Degradation on Rutherford Cabling of Nb$_{\text{3}}$Sn Wires
/ Hopkins, Simon C (CERN) ; Medina-Clavijo, Bentejui (CERN) ; Rastoll, Cristin (CERN ; U. Bourgogne) ; Rodia, Davide (CERN ; Geneva U.) ; Malabaila, Marina (CERN) ; Barth, Christian (CERN) ; Fleiter, Jerome (CERN) ; Boutboul, Thierry (CERN) ; Ballarino, Amalia (CERN)
In the production of Rutherford cables, Nb 3 Sn strands are subjected to severe deformation; and to evaluate this degradation prior to cabling, uniaxial rolling with a thickness reduction of ∼15% has often been used. The effects of this deformation on superconducting performance differ significantly between wire designs. [...]
2024 - 8 p.
- Published in : IEEE Trans. Appl. Supercond. 34 (2024) 6001308
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X-Ray Absorption Spectroscopy to Investigate Precipitated Oxides in Nb3Sn Wires With an Internal Oxygen Source
/ Bovone, G (Geneva U.) ; Buta, F (Geneva U.) ; Lonardo, F (Geneva U.) ; Bonura, M (Geneva U.) ; Borca, C N (PSI, Villigen) ; Huthwelker, T (PSI, Villigen) ; Hopkins, S C (CERN) ; Ballarino, A (CERN) ; Boutboul, T (CERN) ; Senatore, C (Geneva U.)
Internal oxidation can achieve significantly enhanced Jcin Nb3Sn wires, but the mechanism of oxygen transport and oxide precipitation is not fully understood. Our investigation employs X-ray Absorption Near-Edge Structure (XANES) spectroscopy, revealing insights into the oxidation of Zr and its interaction with oxygen in different areas of the wire cross section. [...]
2024 - 5 p.
- Published in : IEEE Trans. Appl. Supercond. 34 (2024) 6000205
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Influence of the Heat Treatment on the Layer JC of Internal-Sn Nb3Sn Wires With Internally Oxidized Nanoparticles
/ Lonardo, F (Geneva U.) ; Bovone, G (Geneva U.) ; Buta, F (Geneva U.) ; Bonura, M (Geneva U.) ; Bagni, T (Geneva U. ; Uppsala U.) ; Medina-Clavijo, B (CERN) ; Ballarino, A (CERN) ; Hopkins, S C (CERN) ; Boutboul, T (CERN) ; Senatore, C (Geneva U.)
We evaluated various heat treatments (HT) for maximizing the Nb3Sn layer thickness while retaining a refined grain microstructure in low filament count internal-Sn Nb3Sn Rod-In-Tube wires with internally oxidized nanoparticles. These wires were manufactured in our laboratory using SnO2as oxygen source and Nb alloys containing Ta and Zr or Hf. [...]
2024 - 5 p.
- Published in : IEEE Trans. Appl. Supercond. 34 (2024) 6000305
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Influence of Axial Strain and Transverse Compressive Load on Critical Current of Nb3Sn Wires for the FCC
/ Nakamoto, M (Sokendai, Tsukuba) ; Sugano, M (KEK, Tsukuba) ; Dhakarwal, M (KEK, Tsukuba) ; Ogitsu, T (KEK, Tsukuba) ; Nishijima, G (Tsukuba Magnet Lab.) ; Awaji, S (Tohoku U. (main)) ; Kawashima, S (Kobe Steel) ; Hopkins, S C (CERN) ; Ballarino, A (CERN)
Nb 3 Sn superconducting wires are under consideration for producing high field accelerator magnets for the proposed Future Circular Collider (FCC) due to their high critical field. R&D; studies are ongoing worldwide with a target non-Cu critical current density ( Jc ) of 1500 A/mm 2 at 4.2 K, 16 T. [...]
2023 - 5 p.
- Published in : IEEE Trans. Appl. Supercond. 33 (2023) 8400505
In : Applied Superconductivity Conference, Honolulu, Hawaii, United States, 23 - 28 Oct 2022, pp.8400505
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5.
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Effects of the oxygen source configuration on the superconducting properties of internally-oxidized internal-Sn Nb$_{3}$Sn wires
/ Bovone, G (Geneva U.) ; Buta, F (Geneva U.) ; Lonardo, F (Geneva U.) ; Bagni, T (Geneva U.) ; Bonura, M (Geneva U.) ; LeBoeuf, D (LNCMI, Grenoble) ; Hopkins, S C (CERN) ; Boutboul, T (CERN) ; Ballarino, A (CERN) ; Senatore, C (Geneva U.)
We successfully manufactured 12-filament rod-in-tube Nb$_{3}$Sn wires with oxide nanoparticles formed by the internal oxidation method. We employed Nb-7.5 wt%Ta-1 wt%Zr and Nb-7.5 wt%Ta-2 wt% Hf alloys along with oxygen sources (OSs) in two different configurations—in the core of Nb filaments (coreOS) and at the boundary between the filaments and the Cu tube (annularOS)—to assess the influence of the OS layout on the superconducting properties and grain size. [...]
2023 - 11 p.
- Published in : Supercond. Sci. Technol. 36 (2023) 095018
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Analysis of inhomogeneities in Nb$_{3}$Sn wires by combined SEM and SHPM and their impact on J $_{c}$ and T $_{c}$
/ Pfeiffer, S (Vienna, Tech. U. ; CERN) ; Baumgartner, T (Vienna, Tech. U., Atominst.) ; Löffler, S (Vienna, Tech. U.) ; Stöger-Pollach, M (Vienna, Tech. U.) ; Hopkins, S C (CERN) ; Ballarino, A (CERN) ; Eisterer, M (Vienna, Tech. U., Atominst.) ; Bernardi, J (Vienna, Tech. U.)
Abstract
We demonstrate the combined use of scanning electron microscopy (SEM) and scanning Hall probe microscopy (SHPM) to analyse inhomogeneities in Nb3Sn wires. Inhomogeneities of the A15 phase in Nb3Sn sub-elements of a Ti-alloyed Restacked Rod Process wire and a Ta-alloyed Powder-In-Tube wire are investigated. [...]
2023 - 11 p.
- Published in : Supercond. Sci. Technol. 36 (2023) 045008
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Very high upper critical fields and enhanced critical current densities in Nb$_3$Sn superconductors based on Nb–Ta–Zr alloys and internal oxidation
/ Buta, F (U. Geneva (main)) ; Bonura, M (U. Geneva (main)) ; Matera, D (U. Geneva (main)) ; Bovone, G (U. Geneva (main)) ; Ballarino, A (CERN) ; Hopkins, S C (CERN) ; Bordini, B (CERN) ; Chaud, X (Natl. High Mag. Field Lab.) ; Senatore, C (U. Geneva (main))
The inhibition of Nb$_3$Sn grain growth in the presence of ZrO$_2$ nanoparticles appears to be one of
the most promising method for pushing the critical current densities of Nb$_3$Sn superconducting
wires to levels that meet the requirements set for the Future Circular Collider. We have investigated
the effect of ZrO$_2$ nanoparticles formed by the internal oxidation of Zr on the superconducting
properties and microstructure of Nb3Sn formed from Nb-1 wt%Zr, Nb-7.5 wt%Ta,
Nb-7.5 wt%Ta-1 wt%Zr and Nb-7.5 wt%Ta-2 wt%Zr alloys. [...]
2021 - 14 p.
- Published in : J. Phys. Mater. 4 (2021) 025003
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Weak acid leaching of MgB$_2$ to purify magnesiothermic boron powder
/ Capra, Marco (Genoa U.) ; Bovone, Gianmarco (CNR, Italy) ; Loria, Federico (CNR, Italy) ; Bernini, Cristina (CNR, Italy) ; Hopkins, Simon C (CERN) ; Ballarino, Amalia (CERN) ; Tropeano, Matteo (ASG Supercond., Genova) ; Tumino, Andrea (ASG Supercond., Genova) ; Grasso, Gianni (ASG Supercond., Genova) ; Ferdeghini, Carlo (CNR, Italy) et al.
We have established a new procedure for recovering boron contained in oxidized MgB$_2$ phase. Incorrect conditions of synthesis or conservation, or excess impurities in precursors, can lead to MgO formation with consequent degradation of superconducting properties, thus representing a possible problem in the industrial production of MgB$_2$ conductors following the ex-situ PIT process. [...]
2021
- Published in : Materials Today Communications 26 (2021) 101731
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