Regular Articles

Full Text / References

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 INAGAKI¹⁾, Masakazu TAKAYAMA²⁾, Kiyohiko NISHIMURA³⁾, Yasuhiro SUZUKI³⁾, Masayuki YOKOYAMA³⁾ and Hiromi TAKAHASHI³⁾

Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan

1)

Research Institute for Applied Mechanics Kyushu University 6-1 Kasuga-kouen, Kasuga, Fukuoka 816-8580, Japan

2)

Akita Prefectural University, Honjyo, Akita 015-0055, Japan

3)

National Institute for Fusion Science,322-6 Oroshi-cho, Toki 509-5292, Japan

(Received 21 December 2009 / Accepted 9 April 2010 / Published 10 December 2010)

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.

Copyright (c) 2010 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

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

DOI: 10.1585/pfr.5.S2041

Full Text

PDF format (1.5Mbytes)

References

• [1] T. E. Evans et al., Phys. Rev. Lett. 92, 235003 (2004).
• [2] S. Kitajima et al., Nucl. Fusion 46, 200 (2006).
• [3] H. Takahashi et al., Plasma Phys. Control. Fusion 48, 39 (2006).
• [4] S. Kitajima et al., Fusion Sci. Technol. 50, 201 (2006).
• [5] S. Kitajima et al., Plasma Fusion Res. 3, S1027 (2008).
• [6] Y. Tanaka et al., Plasma Fusion Res. 2, S1019 (2007).
• [7] Y. Tanaka et al., Plasma Phys. Control. Fusion 48, A285 (2006).

This paper may be cited as follows:

Sumio KITAJIMA, Junya SATO, Keiichi ISHII, Takanori AMBO, Mamoru KANNO, Atsushi OKAMOTO, Mamiko SASAO, Shigeru INAGAKI, Masakazu TAKAYAMA, Kiyohiko NISHIMURA, Yasuhiro SUZUKI, Masayuki YOKOYAMA and Hiromi TAKAHASHI, Plasma Fusion Res. 5, S2041 (2010).