Effects of Magnetic Islands Produced by External Perturbation Fields in the Tohoku University Heliac

Sumio KITAJIMA; Junya SATO; Keiichi ISHII; Takanori AMBO; Mamoru KANNO; Atsushi OKAMOTO; Mamiko SASAO; Shigeru INAGAKI; Masakazu TAKAYAMA; Kiyohiko NISHIMURA; Yasuhiro SUZUKI; Masayuki YOKOYAMA; Hiromi TAKAHASHI

doi:10.1585/pfr.5.S2041

Regular Articles

Effects of Magnetic Islands Produced by External Perturbation Fields in the Tohoku University Heliac

Sumio KITAJIMA, Junya SATO, Keiichi ISHII, Takanori AMBO, Mamoru KANNO, Atsushi OKAMOTO, Mamiko SASAO, Shigeru INAGAKI, Masakazu TAKAYAMA, Kiyohiko NISHIMURA, Yasuhiro SUZUKI, Masayuki YOKOYAMA, Hiromi TAKAHASHI

Author information

Sumio KITAJIMA
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
Junya SATO
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
Keiichi ISHII
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
Takanori AMBO
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
Mamoru KANNO
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
Atsushi OKAMOTO
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
Mamiko SASAO
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
Shigeru INAGAKI
Research Institute for Applied Mechanics Kyushu University 6-1 Kasuga-kouen, Kasuga, Fukuoka 816-8580, Japan
Masakazu TAKAYAMA
Akita Prefectural University, Honjyo, Akita 015-0055, Japan
Kiyohiko NISHIMURA
National Institute for Fusion Science,322-6 Oroshi-cho, Toki 509-5292, Japan
Yasuhiro SUZUKI
National Institute for Fusion Science,322-6 Oroshi-cho, Toki 509-5292, Japan
Masayuki YOKOYAMA
National Institute for Fusion Science,322-6 Oroshi-cho, Toki 509-5292, Japan
Hiromi TAKAHASHI
National Institute for Fusion Science,322-6 Oroshi-cho, Toki 509-5292, Japan

Keywords: stellarator, heliac, magnetic island, poloidal rotation, perturbation field, electrode bias

JOURNAL FREE ACCESS

2010 Volume 5 Pages S2041

DOI https://doi.org/10.1585/pfr.5.S2041

Details

Abstract

Island effects on the plasma periphery due to the external perturbation fields in the Tohoku University Heliac (TU-Heliac) were surveyed. A fixed m = 3 magnetic island was produced by two pairs of external cusp field coils. The electron density decayed from the outer edge of the island after perturbation field application. Radial profiles of the electron temperature and plasma space potential in the island region revealed the magnetic island structure. The radial electric field at the inner edge of the island increased after perturbation field application. The positions of local maxima in the plasma space potential profile were in good agreement with the position of the n/m = 5/3 rational surface. The potential profile in the island grew with the perturbation field strength. The full width at half maximum of the potential profile depended on the square root of the perturbation field coil current.

Corresponding author

Register with J-STAGE for free!