Development of Persistent-Current Mode HTS Coil for the RT-1 Plasma Device

Author

Tosaka, Taizo ; Ohtani, Yasumi ; Ono, Michitaka ; Kuriyama, Toru ; Mizumaki, Shoichi ; Shibui, Masanao ; Nakamoto, Kazunari ; Tachikawa, Nobuo ; Morikawa, Junji ; Ogawa, Yuichi ; Yoshida, Zensho

Author_Institution

Power & Ind. Syst. Res. & Dev. Center, Toshiba Corp., Yokohama

Volume

16

Issue

2

fYear

2006

fDate

6/1/2006 12:00:00 AM

Firstpage

910

Lastpage

913

Abstract

The plasma confinement device "RT-1" which had a high temperature superconducting (HTS) floating magnet was constructed for advanced high-beta plasma and fusion research at the University of Tokyo. The high temperature superconducting (HTS) floating magnet is magnetically levitated inside the plasma vacuum vessel. Plasma is confined by a magnetic dipole field around the HTS floating magnet. The HTS floating magnet is operated in persistent-current mode and it consists of an HTS coil, an HTS persistent-current switch (PCS), a pair of demountable joints of current leads, detachable joints of a cooling tube, a thermal shield and a vacuum vessel. The HTS coil and the PCS and the thermal shield are cooled below 20 K by a flow of helium gas through the cooling tube. The floating HTS magnet is designed to operate in the temperature range from 20 K to 30 K without being cooled while it is levitated. We fabricated a persistent-current HTS coil that consists of the HTS coil and the PCS. Persistent-current operations and protection tests were conducted with the persistent-current HTS coil before it was mounted in the floating magnet cryostat. The current-decay rate was 0.9% in an 8 hour operation. The coil energy was safely discharged by inducing PCS quench in a protection test

Keywords

barium compounds; bismuth compounds; calcium compounds; copper compounds; fusion reactor design; high-temperature superconductors; lead compounds; persistent currents; plasma confinement; plasma switches; strontium compounds; superconducting coils; superconducting magnets; yttrium compounds; Bi2223; Bi₂PbSr₂Ca₂Cu₃O ₁₀; RT-1 plasma device; YBCO; YBa₂Cu₃O_7-delta; coil energy; cooling tube; demountable joints; detachable joints; floating magnet cryostat; helium gas; high temperature superconducting floating magnet; magnetic dipole field; persistent-current mode HTS coil; persistent-current operations; persistent-current switch; plasma confinement device; plasma vacuum vessel; protection tests; thermal shield; High temperature superconductors; Magnetic confinement; Magnetic levitation; Magnetic shielding; Personal communication networks; Plasma confinement; Plasma devices; Plasma temperature; Superconducting coils; Superconducting magnets; Bi2223; HTS; PCS; RT-1; YBCO; fusion; internal coil; persistent-current mode; plasma confinement;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2006.873272

Filename

1642995