Evaluation and Analysis of Transport Characteristics of Large-Current High-Temperature Superconducting Conductors for Fusion Reactor

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K14691
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 14020:Nuclear fusion-related
• Research Institution: National Institute for Fusion Science
• Principal Investigator: Onodera Yuta 核融合科学研究所, 研究部, 助教 (70823847)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 高温超伝導線材 / 高温超伝導導体 / 磁化計測 / 非破壊検査

Outline of Final Research Achievements

This study aims to develop large-current, high-temperature superconducting conductors for fusion reactor magnets. The research focuses on thoroughly evaluating the current-carrying characteristics of the strands, prototyping the conductors, and establishing non-destructive, non-contact techniques for assessing the current-carrying characteristics of the conductors themselves. To achieve these objectives, we developed an apparatus utilizing pickup coils to evaluate the current-carrying characteristics of the strands under various magnetic fields, temperatures, and magnetic field application angles. Additionally, we proposed an evaluation method based on magnetization techniques using the rotational magnetization method. The critical current value of the prototype conductor was assessed based on the obtained current-carrying characteristics of the strands. Furthermore, we demonstrated that the rotational magnetization method enables the evaluation of defect positions within the strands.

Free Research Field

超伝導工学

Academic Significance and Societal Importance of the Research Achievements

核融合炉用マグネットに用いられる高温超伝導線材は、従来線材を凌駕する高磁界特性を有している。そのため大電流領域では一般的な通電法による測定が困難となる。そこで相補的な手法として磁化法を用いた計測装置を製作した。ピックアップコイルと回転磁化法により任意の磁場・温度・磁場印加角度における素線の通電特性を評価可能となる。また、導体の健全性を非破壊・非接触で評価する手法は、導体そのものが開発段階であることから確立できていない。そこで、回転磁化法を用いた本評価手法を適用することで劣化位置を把握でき、導体開発へのフィードバックにつなげることができると考える。