Cross-field demagnetization of stacks of tapes: 3D modeling and measurements
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Publication Date
2020-04-01Journal Title
Superconductor Science and Technology
ISSN
0953-2048
Volume
33
Issue
4
Type
Article
This Version
AM
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Kapolka, M., Pardo, E., Grilli, F., Baskys, A., Climente-Alarcon, V., Dadhich, A., & Glowacki, B. (2020). Cross-field demagnetization of stacks of tapes: 3D modeling and measurements. Superconductor Science and Technology, 33 (4)https://doi.org/10.1088/1361-6668/ab5aca
Abstract
Stacks of superconducting tapes can trap much higher magnetic fields than conventional magnets. This makes them very promising for motors and generators. However, ripple magnetic fields in these machines present a cross-field component that demagnetizes the stacks. At present, there is no quantitative agreement between measurements and modeling of cross-field demagnetization, mainly due to the need of a 3D model that takes the end e ects and real micron-thick superconducting layer into account. This article presents 3D modeling and measurements of cross-field demagnetization in stacks of up to 5 tapes and initial magnetization modeling of stacks of up to 15 tapes. 3D modeling of the cross-field demagnetization explicitly shows that the critical current density, Jc, in the direction perpendicular to the tape surface does not play a role in cross-field demagnetization. When taking the measured anisotropic magnetic field dependence of Jc into account, 3D calculations agree with measurements with less than 4 % deviation, while the error of 2D modeling is much higher. Then, our 3D numerical methods can realistically predict cross-field demagnetization. Due to the force-free configuration of part of the current density, J, in the stack, better agreement with experiments will probably require measuring the Jc anisotropy for the whole solid angle range, including J parallel to the magnetic field.
Sponsorship
European Union's Horizon 2020 research innovation program under grant
agreement No 7231119 (ASuMED consortium).
Funder references
EPSRC (EP/P000738/1)
European Commission Horizon 2020 (H2020) Societal Challenges (723119)
Identifiers
External DOI: https://doi.org/10.1088/1361-6668/ab5aca
This record's URL: https://www.repository.cam.ac.uk/handle/1810/299242
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