Author :
Takahashi, Y. ; Nunoya, Y. ; Nishijima, G. ; Koizumi, N. ; Matsui, K. ; Ando, T. ; Hiyama, T. ; Nakajima, H. ; Kato, T. ; Isono, T. ; Sugimoto, M. ; Kawano, K. ; Oshikiri, M. ; Seki, S. ; Wakabayashi, H. ; Takano, K. ; Uno, Y. ; Nakamura, T. ; Tsuji, H. ;
Author_Institution :
Naka Fusion Res. Establ., JAERI, Ibaraki, Japan
Abstract :
The conductor joint is one of the key technologies for superconducting coils. A butt type joint has been successfully developed for the ITER magnets. The 46 kA Nb/sub 3/Sn conductors are connected by the diffusion bonding technique in vacuum, after the reaction of Nb/sub 3/Sn. The advantage of this joint is low losses against pulse field, because the compacted part is very small compared with other types of joint. 15 butt joints have already been fabricated in the ITER CS Model Coil. According to the test results of the full-size conductor samples, these butt joints will be operated stably in the pulse operation, because the temperature increase due to ac losses and Joule heating by joint resistance is very small and the joint has a sufficiently high temperature margin.
Keywords :
Tokamak devices; fusion reactor design; niobium alloys; superconducting coils; tin alloys; 46 kA; ITER; Joule heating; Model Coils; Nb/sub 3/Sn; Nb/sub 3/Sn conductor joint; ac losses; butt type joint; diffusion bonding; joint resistance; temperature; Conductors; Diffusion bonding; Magnets; Niobium; Resistance heating; Superconducting coils; Temperature; Testing; Tin; Vacuum technology;
