Asymmetrical normal-zone propagation observed in the aluminum-stabilized superconductor for the LHD helical coils

Author

Yanagi, Nagato ; Imagawa, Shinsaku ; Hishinuma, Yoshimitsu ; Seo, Kazutaka ; Takahata, Kazuya ; Hamaguchi, Shinji ; Iwamoto, Akifumi ; Chikaraishi, Hirotaka ; Tamura, Hitoshi ; Moriuchi, Sadatomo ; Yamada, Shuichi ; Nishimura, Arata ; Mito, Toshiyuki ; Mo

Author_Institution

National Inst. for Fusion Sci., Toki, Japan

Volume

14

Issue

2

fYear

2004

fDate

6/1/2004 12:00:00 AM

Firstpage

1507

Lastpage

1510

Abstract

Transient normal-transitions have been observed in the superconducting helical coils of the Large Helical Device (LHD). Stability tests have been performed for an R&D coil as an upgrading program of LHD, and we observed asymmetrical propagation of an initiated normal-zone. In some conditions, a normal-zone propagates only in one direction along the conductor and it hence forms a traveling normal-zone. The Hall electric field generated in the longitudinal direction in the aluminum stabilizer is a plausible candidate to explain the observed asymmetrical normal-zone propagation.

Keywords

Hall effect; aluminium; electric fields; electrical conductivity; fusion reactor design; stability; stellarators; superconducting coils; superconducting magnets; Al; LHD helical coils; Large Helical Device; R&D coil; aluminum stabilizer; aluminum-stabilized superconductor; asymmetrical propagation; dynamic stability; longitudinal Hall electric field; longitudinal direction; stability tests; superconducting helical coils; transient normal-transitions; traveling normal-zone; Aluminum; Conductors; Cryogenics; High temperature superconductors; Plasma temperature; Research and development; Stability; Superconducting cables; Superconducting coils; Testing; Aluminum stabilizer; LHD; dynamic stability; helical coils; longitudinal Hall electric field; traveling normal-zone;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2004.830673

Filename

1325084