High-temperature-superconductor technology toward high-speed and high-field beam scanning magnets for heavy-ion cancer therapy

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H00245
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: Kyoto University
• Principal Investigator: Amemiya Naoyuki 京都大学, 工学研究科, 教授 (10222697)
• Co-Investigator(Kenkyū-buntansha): 曽我部 友輔 京都大学, 工学研究科, 助教 (40847216)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 超伝導 / 電磁石 / 加速器 / がん治療 / 交流 / 交流損失 / 遮蔽電流磁界

Outline of Final Research Achievements

We have developed a conceptual design of high-speed and high-field beam scanning magnets for heavy-ion cancer therapy.
By winding coils using SCSC cables, in which multifilamented and copper-plated high-temperature superconducting coated conductor are multilayered wound around a circular core, we have solved the following bottlenecks: ac loss due to the movement of fluxoids during magnetic field changing, deterioration of magnetic field accuracy due to large antimagnetization caused by the tape shape of the coated conductors, and high terminal voltage due to large interlinkage flux and high frequency. Through a combined approach of experiments and electromagneitc field analyses, we clarified the electromagnetic phenomena of magnets composed of coils wound with SCSC cables and iron yokes, and established guidelines for reducing ac losses and shielding-current-induced fields.

Free Research Field

応用超伝導

Academic Significance and Societal Importance of the Research Achievements

銅分流層複合マルチフィラメント薄膜高温超伝導線をスパイラル状に巻いた導体であるSCSCケーブルを用いて高速変動高磁界電磁石技術の構築をはかるという独自性の高い研究である。また、周波数200 Hz、磁束密度1 Tの高速変動高磁界を大空間に発生する技術は存在せず、これまでほぼ直流の応用に限定されていた超伝導電磁石の応用領域を200 Hzという高速変動高磁界の発生に大きく広げる可能性を秘めた成果であり、本研究の研究成果の学術的意義は大きい。
さらに、本研究の成果をもとに回転ガントリーの格段の小型化を通して重粒子線がん治療の普及が進むことが期待され、健康長寿社会に貢献するという大きな社会的意義をもつ。