Study on Stability of Voltage between Conductors and Cooling in JT-60SA Poloidal Field coil

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K04422
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21010:Power engineering-related
• Research Institution: Sophia University
• Principal Investigator: NAKAMURA KAZUYA 上智大学, 理工学部, 教授 (00407339)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 超伝導工学 / 核融合実験装置 / JT-60SA

Outline of Final Research Achievements

The superconducting magnet system for the JT-60 Super Advanced (JT-60SA) consists of the poloidal field coil (PF) and toroidal field coil (TF). The PF coil consists of the central solenoid (CS) and equilibrium field coils. When a time-varying magnetic field is applied to the coils, the resonance phenomenon and AC losses in the coil occur, and the temperature margin of the coil decreases. And hence, to protect the coil system, it is necessary to understand the voltage behavior and temperature margin of the coil. The results of the work are as follows; (1) A circuit simulation model of the JT-60SA PF coils with the passive structures (cryostat, vacuum vessel and stabilizing plate) was developed. As a result, the influence of the passive structures on the layer voltage in the PF coils is small. (2) we developed an analytical model to estimate the temperature distribution for the helium, strands, and jacket in the conductor from the measurement of the JT-60SA CSMC cool-down test.

Free Research Field

電気工学

Academic Significance and Societal Importance of the Research Achievements

核融合の研究開発は様々な機関で行われている。現在，国際熱核融合実験炉(ITER)計画が各国の協力のもと進められている。本研究で主に用いられるJT-60SA CSの設計概念はITERのCSモジュールと同一であるため，それらのコイルの電気的安定性及び冷却安定性の評価は実機運転時に非常に重要な位置づけと考えられる。これらの結果はITERのみならず将来の実証炉に用いられる大型超伝導コイルの礎となる。