Fundamental Investigation for Application of Original Methods Eliminating Screening-Current-Induced Fields to Superconducting Coils for Magnetic Resonance Imaging System

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K12671
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 90130:Medical systems-related
• Research Institution: Tokyo University of Science, Yamaguchi
• Principal Investigator: KAJIKAWA Kazuhiro 山陽小野田市立山口東京理科大学, 工学部, 教授 (10294894)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 高温超伝導線 / テープ形状 / 遮蔽電流 / 磁化 / 消磁 / 同軸配置 / トロイド配置 / MRI装置

Outline of Final Research Achievements

When high temperature superconducting coils for magnetic resonance imaging (MRI) system are constructed, the screening-current-induced field that produces special inhomogeneity and temporal decay is one of problems to be solved. Original methods to eliminate the screening-current-induced fields have been proposed and validated using fabricated small single coils. In this study, in order to validate the proposed methods to eliminate the screening-current-induced fields in the high temperature superconducting coils for MRI system, which usually consist of several sets of element coils, we carried out experiments for two arrangements of shaking coils and numerical analyses on the magnetic interaction between the coils affecting the elimination of screening-current-induced field.

Free Research Field

超伝導工学

Academic Significance and Societal Importance of the Research Achievements

実験と数値解析の結果、消磁コイルが作る外部磁場により高温超伝導コイルに誘起される遮蔽電流磁場の大きさは非常に小さく、提案する遮蔽電流磁場消磁法が複数個のコイル群で構成されるMRI装置用高温超伝導コイルに対しても適用可能なことを明らかとした。現在国内外の病院に幅広く導入されているMRI装置では低温超伝導コイルを液体ヘリウムで冷却しているが、高温超伝導化により希少で高価なヘリウムを使用しないMRI装置の実現に一歩近づいた。