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内容記述 |
The JT-60 Super Advanced (JT-60SA) was constructed as part of the project for early realization of fusion energy and conducts supportive and complementary works for the ITER. The superconducting coil system of the JT-60SA comprises the toroidal field (TF) coils, equilibrium field (EF) coils and central solenoid (CS) modules. Each TF coil is monitored by the quench detection (QD) system based on voltage measurement which compares two voltages at adjacent TF coils with the bridge circuit. The inductive voltage caused by the EF coils does not occur in the TF coils because the TF coils are orthogonal to the EF coils as a design. However, when the EF coil was energized during the integrated commissioning test, the QD voltage in the TF coils exceeded the threshold. The magnetic flux of the EF coils through the TF coils may occur due to an error in the installation and the design value of clearance. As a result, inductive voltage in the TF coils can be generated. To understand the effect of other coils on the QD system in the TF coils and ensure the stable operation of the JT-60SA, it is important to investigate the cause of the inductive voltage in the TF coils. In this study, we created a simulation model including the TF and EF coils, and the mutual inductance between the TF and EF coils was calculated. Furthermore, the inductive voltage caused by the misalignment of the TF coils was quantitatively estimated. |
