AC losses of an HTS insert in a 25-T cryogen-free superconducting magnet

S. Awaji, Kazuhiro Kajikawa, K. Watanabe, H. Oguro, T. Mitose, S. Fujita, M. Daibo, Y. Iijima, H. Miyazaki, M. Takahashi, S. Ioka

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

A 25-T cryogen-free superconducting magnet (25T-CSM) is being developed at the High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University. In the case of a cryogen-free superconducting magnet, the coil temperature rises during a sweep of an operating current due to ac losses. Hence, the ac loss estimation is very important for the cooling design. The critical current density and the magnetization of Gd123 tapes at 4.2 K were measured in order to estimate the ac loss of a Gd123 insert of the 25T-CSM. The ac loss is actually the hysteresis loss, which are calculated from the $J-{c} $ properties taking the magnetic field distribution in the Gd123 coil into account. Regarding the effect of tape stacking (or winding) in a pancake coil, the slab approximation can be used for hysteresis loss calculation. In the case of slab model, the full penetration field at the center of the tape becomes higher than the maximum applied magnetic field in the most part of the coil. As a result, the hysteresis loss increases with increasing a magnetic field when the magnet energizes. The hysteresis losses assuming the slab model, however, show an opposite field dependence to those calculated from the strip model without the stacking effect. Hence, the ac loss of 5 W is estimated when the magnet energizes to 25.5 T within 60 min.

Original languageEnglish
Article number6945815
JournalIEEE Transactions on Applied Superconductivity
Volume25
Issue number3
DOIs
Publication statusPublished - Jun 1 2015

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Superconducting magnets
superconducting magnets
inserts
alternating current
Hysteresis
coils
hysteresis
Tapes
tapes
slabs
Magnetic fields
Magnets
magnets
magnetic fields
Superconducting materials
Magnetization
strip
critical current
penetration
current density

All Science Journal Classification (ASJC) codes

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

Cite this

AC losses of an HTS insert in a 25-T cryogen-free superconducting magnet. / Awaji, S.; Kajikawa, Kazuhiro; Watanabe, K.; Oguro, H.; Mitose, T.; Fujita, S.; Daibo, M.; Iijima, Y.; Miyazaki, H.; Takahashi, M.; Ioka, S.

In: IEEE Transactions on Applied Superconductivity, Vol. 25, No. 3, 6945815, 01.06.2015.

Research output: Contribution to journalArticle

Awaji, S, Kajikawa, K, Watanabe, K, Oguro, H, Mitose, T, Fujita, S, Daibo, M, Iijima, Y, Miyazaki, H, Takahashi, M & Ioka, S 2015, 'AC losses of an HTS insert in a 25-T cryogen-free superconducting magnet', IEEE Transactions on Applied Superconductivity, vol. 25, no. 3, 6945815. https://doi.org/10.1109/TASC.2014.2366552
Awaji, S. ; Kajikawa, Kazuhiro ; Watanabe, K. ; Oguro, H. ; Mitose, T. ; Fujita, S. ; Daibo, M. ; Iijima, Y. ; Miyazaki, H. ; Takahashi, M. ; Ioka, S. / AC losses of an HTS insert in a 25-T cryogen-free superconducting magnet. In: IEEE Transactions on Applied Superconductivity. 2015 ; Vol. 25, No. 3.
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