研究者業績

高尾 智明

タカオ トモアキ  (Takao Tomoaki)

基本情報

所属
上智大学 理工学部 機能創造理工学科 教授
学位
工学修士(横浜国立大学)
博士(工学)(横浜国立大学)

連絡先
t-takaosophia.ac.jp
研究者番号
30245790
J-GLOBAL ID
200901090041872532
researchmap会員ID
1000073284

1993年度まで 超電導線の寸法不整と導線の動きの研究
94~98年度 超電導コイルの安定化の研究
99~2001年度 コイルに生じる交流損の研究
2002年度以降 Bi線の剛性と劣化の研究

教育活動
 ・電気回路・・・計算力をつける事を主眼に演習を重視した授業。
 ・エネルギー工学・・・地球環境とのかかわりを含め、エネルギーと資源などの問題も含めて講義。
     一部だけを強調する性能の良さに捉われず、全体像を把握できる講義を目指す。
 ・電力システム・・・発電および送電が中心テーマ。発電では特に原子力発電の現状と課題を理解させる。
     送電は電力方程式と円線図、故障計算および安定度までを扱う。
研究活動:超伝導工学および極低温材料工学を中心分野に据えた研究
 ・超伝導マグネット・・・直流通電におけるクエンチ電流の向上、交流通電における機械損失低減により
     総合的に安定性向上を目指す。
 ・超伝導線の機械的特性・・・要素技術として、線材表面の摩擦特性および線材の歪特性を検討。
     これらの特性と超伝導線の性能劣化との関係を研究。
 ・核融合関連研究・・・超伝導マグネット用の極低温構造材料を炉工学の視点により研究。

(研究テーマ)
超電導電磁石の安定性
超電導体の熱特性
超電導体の機械特性

(共同・受託研究希望テーマ)
超電導工学


研究キーワード

 7

論文

 67
  • T. Onji, R. Inomata, T. Yagai, T. Takao, Y. Makida, T. Shintomi, N. Hirano, T. Komagome, T. Hamajima
    IEEE Transactions on Applied Superconductivity 33(5) 1-5 2023年8月  
  • Y Yanagisawa, R Piao, Y Suetomi, T Yamazaki, K Yamagishi, T Ueno, T Takao, K Ohki, T Yamaguchi, T Nagaishi, H Kitaguchi, Y Miyoshi, M Yoshikawa, M Hamada, K Saito, K Hachitani, Y Ishii, H Maeda
    Superconductor Science and Technology 34(11) 115006-115006 2021年11月1日  
    <jats:title>Abstract</jats:title> <jats:p>This paper describes the first persistent-mode medium magnetic field (400 MHz; 9.39 T) nuclear magnetic resonance (NMR) magnet which uses superconducting joints between high-temperature superconductors (HTSs). As the ultimate goal, we aim to develop a high-resolution 1.3 GHz (30.5 T) NMR magnet operated in the persistent-mode. The magnet requires superconducting joints between HTSs and those between an HTS and a low-temperature superconductor (LTS). Towards this goal, we have been developing persistent-mode HTS inner coils to be operated in a 400 MHz (9.39 T) NMR magnet and here we present the first prototype inner coil wound with a single piece (RE = rare earth)Ba<jats:sub>2</jats:sub>Cu<jats:sub>3</jats:sub>O<jats:sub>7−<jats:italic>x</jats:italic> </jats:sub> (REBCO) conductor. The coil and a REBCO persistent current switch are connected with intermediate grown superconducting joints with high critical currents in external magnetic fields. To evaluate the performance of the joints in an ultimately stable and homogeneous magnetic field, the coil is operated in the persistent-mode, generating 0.1 T, in a 9.3 T background magnetic field of a persistent-mode LTS outer coil. The magnetic field drift over two years of the 400 MHz LTS/REBCO NMR magnet is as small as ∼1 ppm, giving high-resolution NMR spectra. The magnetic field drift rate over the second year was 0.03 × 10<jats:sup>−3</jats:sup> ppm h<jats:sup>−1</jats:sup>, which is more than three orders of magnitude smaller than that required for an NMR magnet, demonstrating that the superconducting joints function satisfactorily in a high-resolution NMR system. The corresponding joint resistance is inferred to be &lt;10<jats:sup>−14</jats:sup> Ω.</jats:p>
  • 谷貝 剛, 高橋 雅史, 高尾 智明, 新冨 孝和, 槙田 康博, 駒込 敏弘, 平野 直樹, 濱島 高太郎, 菊池 章弘, 西島 元, 松本 明善
    低温工学学会誌 56(5) 269-276 2021年5月  査読有り招待有り
    The superconducting Magnetic Energy Storage (SEMS) application still has a great potential to stabilize the utility grid when the uncontrollable power generation from renewable sources increases and power flows change rapidly due to the broad introduction of high-speed response semiconductor switching devices. Along with the development of liquid hydrogen supply chain, the SMES system using MgB2 conductors also attracts great attention at this point. Although the MgB2 wires which have critical temperature of around 39 K have been commercially available with more affordable prices, their bending strain sensitivity is an issue to be solved for fabricating large-scale conductors and coils. The experience of constructing a 10-kJ SMES system using Bi2223 tapes and the successful demonstration of compensating very fast electric power fluctuations in the previous project will help us to develop a larger-scale MgB2 SMES system by investigating conductor and coil design while considering its bending strain sensitivity and mechanism of critical current deterioration to maximize its performance as one of the most promising energy storage devices, following the movement toward a CO2-free environment.
  • T. Onji, A. Ishihara, Y. Kobayashi, M. Tomita, M. Hira, T. Yagai, T. Takao, Y. Makida, T. Shintomi, N. Hirano, T. Komagome, K. Tsukada, T. Hamajima
    Journal of Physics: Conference Series 1559(1) 2020年6月19日  
    Our group has developed a coil using MgB2 wires for SMES. In this paper, a prototype coil using a MgB2 Rutherford-Type stranded conductor was fabricated based on react-And-wind (R&amp W) method. In the R&amp W method, a Rutherford-Type conductor in which nine MgB2 wires were wound at pitch of 450 mm around a copper former were manufactured using reacted wires (performed by Columbus Superconductors SpA), and then coiling was performed. The coil was cooled by conduction cooling and the I-V properties were evaluated under magnetic field. As a result, in the R&amp W method, critical current of a coil was degraded, since making a coil by hand would cause the strain beyond the scope of the assumption which was the marginally allowable bending strain. This result suggests the coil for SMES proposed in ASPCS is difficult to react before twisting, and Rutherford-Type conductors should be fabricated before reacting, which means that coil processing should be performed based on the React after making stranded conductors and Wind method, or the wind-And-react method.
  • H. Toriyama, A. Nomoto, T. Ichikawa, T. Takao, K. Nakamura, O. Tsukamoto, M. Furuse
    Journal of Physics: Conference Series 1559(1) 2020年6月19日  
    An HTS coil quenches despite of the high quench margin. Main origins of unexpected quench of HTS coils are non-reversible local defects, and training effects as in LTS coils are not observed in HTS coils. Therefore, when an HTS coil is quenched before the required coil performance is met, the coil cannot be reused unless the coil is safely protected from quench damage and its operating conditions are readjusted. This paper studies on the conditions to reuse the coil which experienced a quench and is not damaged by the quench to meet the required performance. The study is conducted based on the temperature and current dependences of the coil stability measures of the maximum allowable defect (MAD) and minimum propagating zone (MPZ).

MISC

 213

書籍等出版物

 4

講演・口頭発表等

 23

共同研究・競争的資金等の研究課題

 9

その他

 2