Reduction of Irregular Magnetic Field Generated by Screening Current in REBCO Coil

Ueda, Hiroshi; Saito, Jun; Ariya, Yuta; Mochida, Ayumu; Wang, Tao; Wang, Xudong; Agatsuma, K.; Ishiyama, Atsushi

doi:10.1109/tasc.2014.2375953

Cited by 11 publications

(19 citation statements)

References 6 publications

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“…Although the parameter α c ∝ I c,tape is spatially distributed in a coil, we regard α c to be a spatially averaged value of I c,tape /I c,coil in a coil for simplicity. , 19) and the dashed lines show our theoretical results given by Eq. ( 21) with α c = 1.5.…”

mentioning

confidence: 70%

“…We consider the dependence of the SCIF ratio, |B SC /B TC | ∝ w, on the tape width, w, and our theoretical results are compared with the numerical results from Ueda et al 19) , 26) and the dashed lines show our theoretical results given by Eq. ( 21) with α c = 1.5.…”

mentioning

confidence: 96%

“…[11][12][13][14] A few techniques have been proposed to suppress the effects of the screening-current-induced field (SCIF). [15][16][17][18][19] Numerical computation is used for designing HTS magnets, but huge computational resources and highly advanced numerical techniques are required for precise evaluation of the SCIF. 12,19,20) Theoretical investigation is thus desired to unveil the underlying physics of the SCIF and to provide a simple method to evaluate the SCIF.…”

mentioning

confidence: 99%

“…The inner diameter, outer diameter, and height of coils are 2a 1 = 100 mm, 2a 2 = 170.5 mm, and 2b = 39-79 mm, respectively. 19) J c , the value of Eq. ( 17) is almost unchanged for 1 < α c < 2 except for I t ∼ I c,coil .…”

mentioning

confidence: 99%

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Theoretical evaluation of the screening-current-induced magnetic field in superconducting coils with tape wires

Mawatari

2018

Appl. Phys. Express

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We theoretically investigate the physical mechanism of the screening-current-induced field (SCIF) in solenoid coils wound with superconducting tape wires. We derive the direct relationship between the SCIF and the magnetization of tape wires, and a scaling law for the SCIF and the coil dimensions is demonstrated. A simple analytical expression of the SCIF is obtained as functions of current load factor, tape wire width, and the coil dimensions. We verify that the published data for the precise numerical computation of SCIF are roughly fitted by our theoretical results for flat coils where the height is smaller than the outer diameter.

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confidence: 70%

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confidence: 96%

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confidence: 99%

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confidence: 99%

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Theoretical evaluation of the screening-current-induced magnetic field in superconducting coils with tape wires

Mawatari

2018

Appl. Phys. Express

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“…Its governing equation uses magnetic intensity H as solution variable, and the whole model can be built and solved in commercial FEM software Comsol Multi-physics. T-w model has also been developed for the electromagnetic modelling of HTS, which couples T-formulation (Faraday's law) and integration equation (Biot-Savart Law) [36][37][38][39].…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic modelling using T‐A formulation for high‐temperature superconductor (RE)Ba ₂ Cu ₃ O _x high field magnets

Wang

Bai

et al. 2020

High Voltage

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Second generation (2G) high-temperature superconductor (HTS) (RE)Ba 2 Cu 3 O x (REBCO) shows a great potential in building high field magnets beyond 23.5 T. The electromagnetic modelling is vital for the design of HTS magnet, however, this always suffers the challenge of huge computation for high field magnets with large number of turns. This study presents a novel electromagnetic modelling based on T-A formulation for REBCO magnets with thousands of turns. An equivalent turn method is proposed to reduce the number of turns in calculation, so that the computation cost can be reduced significantly, and meanwhile the key electromagnetic behaviour of HTS magnet can be simulated with enough accuracy. The ramping operation of a fully HTS magnet with 12,000 turns are analysed using both the original T-A model with actual turns and improved T-A model with equivalent turns. The two models show a good agreement on the key electromagnetic behaviours of the magnet: distribution of current density, magnetic fields, screen current induced field and magnetisation loss, so that this improved T-A model using equivalent turns is validated. The T-A modelling of REBCO magnet is a powerful tool for the electromagnetic analysis of industry-scale high field magnets.

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Combination of high hoop stress tolerance and a small screening current-induced field for an advanced Bi-2223 conductor coil at 4.2 K in an external field

Yanagisawa

Iguchi

et al. 2015

Supercond. Sci. Technol.

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An advanced Bi-2223 conductor with Ni–Cr reinforcement is a likely candidate to achieve a compact super-high field nuclear magnetic resonance (NMR) magnet capable of operation beyond 1 GHz (23.5 T). However, the conductors must show both high hoop stress tolerance, typically >300 MPa, and a small screening current-induced magnetic field, both of which are essential for a compact magnet generating a highly accurate field. These two conditions have not yet been demonstrated in a working coil. This is the first paper to systematically investigate both characteristics for a layer-wound coil made with the advanced Bi-2223 conductor operated mainly at 4.2 K in an external field of ≤17 T. The coil tolerated a hoop stress of 370 MPa, even though the conductor had a bending strain corresponding to a diameter of 120 mm. On the other hand, the coil showed a notable screening current-induced field in a low external field, which may be explained by weak-link and direct contacts between highly packed Bi-2223 filaments in the silver matrix. The field sharply decreased with increasing external field between 0–1 T. Thus, the conductor should be useful for inner coils in compact super-high field NMR magnets.

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Reduction of Irregular Magnetic Field Generated by Screening Current in REBCO Coil

Cited by 11 publications

References 6 publications

Theoretical evaluation of the screening-current-induced magnetic field in superconducting coils with tape wires

Theoretical evaluation of the screening-current-induced magnetic field in superconducting coils with tape wires

Electromagnetic modelling using T‐A formulation for high‐temperature superconductor (RE)Ba ₂ Cu ₃ O _x high field magnets

Combination of high hoop stress tolerance and a small screening current-induced field for an advanced Bi-2223 conductor coil at 4.2 K in an external field

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Reduction of Irregular Magnetic Field Generated by Screening Current in REBCO Coil

Cited by 11 publications

References 6 publications

Theoretical evaluation of the screening-current-induced magnetic field in superconducting coils with tape wires

Theoretical evaluation of the screening-current-induced magnetic field in superconducting coils with tape wires

Electromagnetic modelling using T‐A formulation for high‐temperature superconductor (RE)Ba 2 Cu 3 O x high field magnets

Combination of high hoop stress tolerance and a small screening current-induced field for an advanced Bi-2223 conductor coil at 4.2 K in an external field

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Electromagnetic modelling using T‐A formulation for high‐temperature superconductor (RE)Ba ₂ Cu ₃ O _x high field magnets