New Method for Quick Decay of Shielding Current in REBCO Superconducting Coils

Masataka Iwakuma, Y. Tsukigi, K. Nabekura, T. Ueno, R. Shindo, F. Kawahara, S. Honda, K. Tamura, K. Yun, S. Sato, K. Yoshida, A. Tomioka, M. Konno, T. Izumi, T. Machi, A. Ibi

研究成果: ジャーナルへの寄稿記事

6 引用 (Scopus)

抄録

We are developing superconducting magnets for MRI with Re1Ba2Cu3O7-δ (Re: Rare Earth, Y, Gd, Eu, REBCO) superconducting tapes. We intend to operate them in subcooled liquid nitrogen at 65 K. Superconducting magnets for MRI need uniformity of magnetic field in time and space. The disturbance should be mainly caused by the shielding current induced in the wound tapes. To investigate this, we made small test coils with a laser-scribed four-filament EuBCO tape and a nonscribed GdBCO tape. After cooling down to 65 K with subcooled liquid nitrogen and applying a dc bias magnetic field, transport current was applied step by step to the test coil and the magnetic field variation at the coil center was observed. The actual magnetic field followed the variation of transport current with a delay. We derived the fitting expression for the observed field variations. The magnitude and the decay time constant of the shielding current increased with transport current. However, when further increasing transport current close to the critical current, the shielding current decayed quickly. Using this tremendous knowledge, we proposed a new operating method so that the magnetic field reached to the target one in a short time. In addition, the comparison between both coils demonstrated that not only the magnitude of shielding current but also the decay time constant was drastically reduced by scribing.

元の言語英語
記事番号7378405
ジャーナルIEEE Transactions on Applied Superconductivity
26
発行部数4
DOI
出版物ステータス出版済み - 6 1 2016

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Shielding
shielding
coils
Magnetic fields
Tapes
decay
Superconducting magnets
tapes
Liquid nitrogen
Magnetic resonance imaging
magnetic fields
Superconducting tapes
superconducting magnets
liquid nitrogen
time constant
Critical currents
Induced currents
Rare earths
scoring
Superconducting coils

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

これを引用

New Method for Quick Decay of Shielding Current in REBCO Superconducting Coils. / Iwakuma, Masataka; Tsukigi, Y.; Nabekura, K.; Ueno, T.; Shindo, R.; Kawahara, F.; Honda, S.; Tamura, K.; Yun, K.; Sato, S.; Yoshida, K.; Tomioka, A.; Konno, M.; Izumi, T.; Machi, T.; Ibi, A.

:: IEEE Transactions on Applied Superconductivity, 巻 26, 番号 4, 7378405, 01.06.2016.

研究成果: ジャーナルへの寄稿記事

Iwakuma, M, Tsukigi, Y, Nabekura, K, Ueno, T, Shindo, R, Kawahara, F, Honda, S, Tamura, K, Yun, K, Sato, S, Yoshida, K, Tomioka, A, Konno, M, Izumi, T, Machi, T & Ibi, A 2016, 'New Method for Quick Decay of Shielding Current in REBCO Superconducting Coils', IEEE Transactions on Applied Superconductivity, 巻. 26, 番号 4, 7378405. https://doi.org/10.1109/TASC.2015.2512910
Iwakuma, Masataka ; Tsukigi, Y. ; Nabekura, K. ; Ueno, T. ; Shindo, R. ; Kawahara, F. ; Honda, S. ; Tamura, K. ; Yun, K. ; Sato, S. ; Yoshida, K. ; Tomioka, A. ; Konno, M. ; Izumi, T. ; Machi, T. ; Ibi, A. / New Method for Quick Decay of Shielding Current in REBCO Superconducting Coils. :: IEEE Transactions on Applied Superconductivity. 2016 ; 巻 26, 番号 4.
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abstract = "We are developing superconducting magnets for MRI with Re1Ba2Cu3O7-δ (Re: Rare Earth, Y, Gd, Eu, REBCO) superconducting tapes. We intend to operate them in subcooled liquid nitrogen at 65 K. Superconducting magnets for MRI need uniformity of magnetic field in time and space. The disturbance should be mainly caused by the shielding current induced in the wound tapes. To investigate this, we made small test coils with a laser-scribed four-filament EuBCO tape and a nonscribed GdBCO tape. After cooling down to 65 K with subcooled liquid nitrogen and applying a dc bias magnetic field, transport current was applied step by step to the test coil and the magnetic field variation at the coil center was observed. The actual magnetic field followed the variation of transport current with a delay. We derived the fitting expression for the observed field variations. The magnitude and the decay time constant of the shielding current increased with transport current. However, when further increasing transport current close to the critical current, the shielding current decayed quickly. Using this tremendous knowledge, we proposed a new operating method so that the magnetic field reached to the target one in a short time. In addition, the comparison between both coils demonstrated that not only the magnitude of shielding current but also the decay time constant was drastically reduced by scribing.",
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AU - Tsukigi, Y.

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AU - Ueno, T.

AU - Shindo, R.

AU - Kawahara, F.

AU - Honda, S.

AU - Tamura, K.

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AU - Sato, S.

AU - Yoshida, K.

AU - Tomioka, A.

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AU - Izumi, T.

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