Author :
Ando, T. ; Takahashi, Y. ; Okuno, K. ; Tsuji, H. ; Hiyama, T. ; Nishi, M. ; Tada, E. ; Yoshida, K. ; Koizumi, K. ; Nakajima, H. ; Kato, T. ; Sugimoto, M. ; Isono, T. ; Kawano, K. ; Konno, M. ; Yoshida, J. ; Ishida, H. ; Kawagoe, E. ; Kamiyauchi, Y. ; Shim
Author_Institution :
Naka Fusion Res. Establ., JAERI, Ibaraki, Japan
Abstract :
AC losses in the DPC-EX, whose purpose is to demonstrate the applicability of Nb3Sn conductor to poloidal coils for Tokamak fusion machines, were measured, and the results were analyzed. The coil was fabricated with a Nb3Sn cable-in-conduit conductor and has a 1 m inner diameter. The AC loss was 9.4 kW for the pulse operation of a 0-17 kA-0 cycle with a ramp time of 1 s, corresponding to a 6.7-T maximum field and a 6.7-T/s pulse rate. It was 0.14% of the magnetic stored energy. The effective Nb3Sn filament diameter was estimated as 32 μm and the effective time constant of the coupling current within the strand was calculated as 2 ms on the assumption that coupling current between strands is negligible. The limitation of coil current due to AC losses is discussed
Keywords :
Tokamak devices; composite superconductors; fusion reactor materials; fusion reactor theory and design; magnetic leakage; niobium alloys; superconducting cables; superconducting magnets; tin alloys; 0 to 17 kA; 6.7 T; AC losses; DPC-EX; Demo Poloidal Coil; Nb3Sn superconductor; Tokamak fusion machines; cable-in-conduit conductor; coil current; coupling current; Atomic measurements; Conducting materials; Conductors; Copper; Helium; Niobium; Niobium-tin; Superconducting coils; Tin; Tokamaks;
