TY - JOUR
T1 - Numerical Evaluation of Screening Current-Induced Magnetic Field in No-Insulation REBCO Coil Systems
AU - Ueda, Satomi
AU - Ishiyama, Atsushi
AU - Ueda, Hiroshi
AU - Noguchi, So
N1 - Funding Information:
Manuscript received November 28, 2020; revised February 6, 2021; accepted February 28, 2021. Date of publication March 8, 2021; date of current version March 31, 2021. This work was supported by JSPS Grant-in-Aid for Scientific Research(S) from the Ministry of Education, Science, Sports, and Culture (No.18H05244) (Corresponding author: Satomi Ueda.) Satomi Ueda and Atsushi Ishiyama are with the Waseda University, Tokyo 169-8555, Japan (e-mail: atsushi@waseda.jp). Hiroshi Ueda is with the Okayama University, Okayama 700-8530, Japan. So Noguchi is with the Hokkaido University, Sapporo Hokkaido 060-0808, Japan. Color versions of one or more figures in this article are available at https: //doi.org/10.1109/TASC.2021.3064540. Digital Object Identifier 10.1109/TASC.2021.3064540
Publisher Copyright:
© 2002-2011 IEEE.
PY - 2021/8
Y1 - 2021/8
N2 - We have been developing a no-insulation (NI) REBCO coil which is expected to be applied to medical accelerators and magnetic resonance imaging as a technology that can achieve both high thermal stability and high current density. Due to the flat shape and much greater, than the thickness, width of a REBCO-coated conductor, the screening currents are remarkably induced by changing the magnetic flux that penetrates the tape vertically. For insulated (INS) coils, this screening current causes an irregular magnetic field (screening current-induced magnetic field (SCIF)). Also, in the NI coil, an excitation delay occurs because of the current flowing in the radial direction with coil excitation. Therefore, as the cause of irregular magnetic field, it is necessary to simultaneously consider the influence of both the excitation delay and SCIF. In this study, we numerically investigate the magnetic field in the NI coil. The SCIF and an excitation delay reduce magnetic accuracy in the NI coil. Thus, we propose an energization waveform that can improve the magnetic field accuracy even if there is an excitation delay. Besides, we verified its effectiveness.
AB - We have been developing a no-insulation (NI) REBCO coil which is expected to be applied to medical accelerators and magnetic resonance imaging as a technology that can achieve both high thermal stability and high current density. Due to the flat shape and much greater, than the thickness, width of a REBCO-coated conductor, the screening currents are remarkably induced by changing the magnetic flux that penetrates the tape vertically. For insulated (INS) coils, this screening current causes an irregular magnetic field (screening current-induced magnetic field (SCIF)). Also, in the NI coil, an excitation delay occurs because of the current flowing in the radial direction with coil excitation. Therefore, as the cause of irregular magnetic field, it is necessary to simultaneously consider the influence of both the excitation delay and SCIF. In this study, we numerically investigate the magnetic field in the NI coil. The SCIF and an excitation delay reduce magnetic accuracy in the NI coil. Thus, we propose an energization waveform that can improve the magnetic field accuracy even if there is an excitation delay. Besides, we verified its effectiveness.
KW - REBCO-coated conductor
KW - excitation delay
KW - no-insulation coil
KW - screening current-induced magnetic field
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U2 - 10.1109/TASC.2021.3064540
DO - 10.1109/TASC.2021.3064540
M3 - Article
AN - SCOPUS:85102652157
SN - 1051-8223
VL - 31
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 5
M1 - 9372885
ER -