Estimation of the superconducting joint for the forced-cooled superconducting poloidal coil for the large helical device

Author

Hanawa, S. ; Wachi, Y. ; Shibayama, K. ; Shibuya, J. ; Nakamoto, K. ; Kai, T. ; Takahata, K. ; Yamamoto, Jun ; Satow, T. ; Motojima, O.

Author_Institution

Toshiba Corp., Yokohama, Japan

Volume

32

Issue

4

fYear

1996

fDate

7/1/1996 12:00:00 AM

Firstpage

2929

Lastpage

2932

Abstract

We applied a new solid state bonding technique to the joints of the forced-cooled superconducting poloidal coils for LHD. The NbTi/Cu wires of the cable-in-conduit (CIC) conductors were joined superconductively by this technique to realize the low electrical resistance and compactness. We make several joint samples and study the joint condition among the NbTi filaments. By scanning electron microscopy (SEM) we make sure that the filaments are joined with very narrow gaps. We measure the magnetization of the joint using a superconducting quantum interference device and estimate the effective diameter of the filaments to be about 90 μm. This value shows that the joint is magnetically stable by the adiabatic theory

Keywords

fusion reactor design; fusion reactors; magnetisation; multifilamentary superconductors; niobium alloys; scanning electron microscopy; stellarators; superconducting coils; titanium alloys; 90 mum; LHD; NbTi filaments; NbTi-Cu; NbTi/Cu wires; SEM; SQUID; adiabatic theory; cable-in-conduit conductors; filaments effective diameter; forced-cooled superconducting poloidal coil; joint condition; large helical device; low electrical resistance; magnetization; solid state bonding technique; superconducting joint; Bonding forces; Conductors; Niobium compounds; SQUIDs; Scanning electron microscopy; Solid state circuits; Superconducting cables; Superconducting coils; Superconducting filaments and wires; Titanium compounds;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.511489

Filename

511489