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Influence of transverse stress exerted at room temperature on the superconducting properties of Nb$_3$Sn wires
/ Ebermann, P (CERN ; Vienna, Tech. U., Atominst.) ; Baumgartner, T (Vienna, Tech. U., Atominst.) ; Behnsen, J (U. Manchester (main)) ; Daly, M (CERN) ; Terricabras, A Gallifa (CERN) ; Koettig, T (CERN) ; Lackner, F (CERN) ; Scheuerlein, C (CERN) ; Eisterer, M (Vienna, Tech. U., Atominst.)
Results on the irreversible degradation of Rutherford cables caused by transverse stress applied at room temperature have been recently published in the frame of the Future Circular Collider study for the 16 T dipole development programme. In order to investigate the degradation process of Nb3Sn composite superconductors, experiments based on wires of the same type as used in the cable have been launched. [...]
2019 - 18 p.
- Published in : Supercond. Sci. Technol. 32 (2019) 095010
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Irreversible degradation of Nb$_3$Sn Rutherford cables due to transverse compressive stress at room temperature
/ Ebermann, Patrick (CERN ; Vienna, Tech. U., Atominst.) ; Bernardi, Johannes (Vienna, Tech. U.) ; Fleiter, Jerome (CERN) ; Lackner, Friedrich (CERN) ; Meuter, Florian (CERN) ; Pieler, Magdalena (Vienna, Tech. U.) ; Scheuerlein, Christian (CERN) ; Schoerling, Daniel (CERN) ; Wolf, Felix (CERN ; T.U. Bergakademie Freiberg) ; Ballarino, Amalia (CERN) et al.
In the framework of the Future Circular Collider design study for a 100 TeV circular collider, 16 T superconducting bending magnets based on Nb$_3$Sn technology are being developed. A pre-stress on the conductor during magnet assembly at room temperature (RT) is needed to counteract the Lorentz forces during operation. [...]
2018 - 10 p.
- Published in : Supercond. Sci. Technol. 31 (2018) 065009
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3.
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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
Fulltext: PDF;
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4.
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Effects of inhomogeneities on pinning force scaling in Nb$_3$Sn wires
/ Baumgartner, Thomas (Vienna, Tech. U., Atominst.) ; Pfeiffer, S (Vienna, Tech. U.) ; Bernardi, Johannes (Vienna, Tech. U.) ; Ballarino, A (CERN) ; Eisterer, Michael (Vienna, Tech. U., Atominst.)
We analyzed the effects of A-15 phase inhomogeneities, in particular Sn concentration gradients, on the pinning force scaling behavior of Nb3Sn wires. This was accomplished using a software code capable of simulating both magnetization and transport measurements on wires containing sub-elements with an arbitrary (e.g. [...]
2018 - 11 p.
- Published in : Supercond. Sci. Technol. 31 (2018) 084002
Fulltext: pdf - PDF; document - PDF;
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5.
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Onset of Mechanical Degradation due to Transverse Compressive Stress in Nb$_3$Sn Rutherford-Type Cables
/ Puthran, K (CERN ; Karlsruhe U., ITP) ; Barth, C (CERN) ; Ballarino, A (CERN) ; Devred, A (CERN) ; Arndt, T (Karlsruhe U., ITP)
In the framework of the High Field Magnets program at CERN, lower limits of degradative mechanical loads on reacted and impregnated Nb$_3$Sn Rutherford-type cables are being studied with the goal of optimizing the pre-stress applied at room temperature on the accelerator magnets. Coils are loaded during assembly, for instance when transverse load is applied by using a collaring press or the bladder and key technique. Nb$_3$Sn is susceptible to transverse compressive stress, which is the loading condition investigated for this study. [...]
2023 - 6 p.
- Published in : IEEE Trans. Appl. Supercond. 33 (2023) 8400406
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Length Changes of Unconfined Nb$_3$Sn Rutherford Cables During Reaction Heat Treatment
/ Michels, Matthias (CERN) ; Lackner, Friedrich (CERN) ; Scheuerlein, Christian (CERN) ; Carlon Zurita, Alejandro (CERN) ; Ferradas Troitino, Salvador (CERN) ; Bourcey, Nicolas (CERN) ; Savary, Frederic (CERN) ; Tommasini, Davide (CERN)
In order to predict volume changes of Nb3Sn coils during reaction heat treatment (RHT), coefficients of thermal expansion (CTE) of the involved materials need to be known. While the CTEs of bulk materials are widely available, there is a lack of knowledge about the dimensional changes of the Nb3Sn Rutherford cables. [...]
2019 - 5 p.
- Published in : IEEE Trans. Appl. Supercond. 29 (2019) 6000605
In : Applied Superconductivity Conference 2018, Seattle, United States Of America, 28 Oct - 2 Nov 2018, pp.6000605
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8.
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Effect of Applied Compressive Stress and Impregnation Material on Internal Strain and Stress State in Nb$_3$Sn Rutherford Cable Stacks
/ Wolf, Felix (CERN) ; Scheuerlein, Christian (CERN) ; Lorentzon, Marcus (CERN) ; Katzer, Balduin (CERN) ; Hofmann, Michael (Forschungsreaktor Munich) ; Gan, Weimin ; Lackner, Friedrich (CERN) ; Schoerling, Daniel (CERN) ; Tommasini, Davide (CERN) ; Savary, Frederic (CERN) et al.
The Nb3Sn superconductor in accelerator magnets must resist high mechanical stresses. In order to better understand the effect of the coil impregnation system on the stresses exerted on the strain-sensitive Nb3Sn superconductor, we have measured the elastic strain evolution in the conductor constituents under externally applied loads. [...]
2019 - 5 p.
- Published in : IEEE Trans. Appl. Supercond. 29 (2019) 8400605
Fulltext: PDF;
In : Applied Superconductivity Conference 2018, Seattle, United States Of America, 28 Oct - 2 Nov 2018, pp.8400605
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9.
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Mechanical analysis of the collaring process of the 11 T dipole magnet
/ Ferracin, Paolo (CERN) ; Bottura, Luca (CERN) ; Bourcey, Nicolas (CERN) ; Daly, Michael (CERN) ; Devred, Arnaud (CERN) ; Izquierdo Bermudez, Susana (CERN) ; Ferradas Troitino, Jose (CERN) ; Ferradas Troitino, Salvador (CERN) ; Grosclaude, Philippe (CERN) ; Guinchard, Michael (CERN) et al.
As part of the Large Hadron Collider (LHC) accelerator upgrades foreseen by the high luminosity-LHC project, the CERN 11 T program is aimed at replacing standard LHC Nb-Ti main dipole magnets, operating with a bore field of 8.3 T, with pairs of shorter Nb$_3$Sn dipole magnets with a bore field of 11 T and the same total integrated field, thus providing space for additional collimators in the dispersion suppressor region. At the time of the submission of this paper, six single-aperture and two double-aperture short models have been fabricated and tested. [...]
2019 - 5 p.
- Published in : IEEE Trans. Appl. Supercond. 29 (2019) 4002705
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10.
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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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