[Table of Contents]

Plasma and Fusion Research

Volume 5, 021 (2010)

Regular Articles

MHD Instabilities in Current Carrying Heliotron Plasmas
Goshi YAMADA, Yuji NAKAMURA and Katsumi KONDO
Graduate School of Energy Science, Kyoto University, Uji, Kyoto 611-0011, Japan
(Received 20 January 2009 / Accepted 21 January 2010 / Published 14 June 2010)

Abstract

Instabilities in low beta l = 2 heliotron plasmas with peaked toroidal current density profiles are investigated using resistive reduced magnetohydrodynamic equations. Such heliotron plasmas can have a nonmonotonic rotational transform ῑ profile with two ῑ = 2/3 rational surfaces. When the distance between the resonant surfaces is large, resistive instabilities can be found. Current-driven ideal modes with larger growth rates appear when the minimum of the rotational transform becomes just above the rational number 2/3 and there is no resonant surface. The existence of this non-resonant mode is explained by the expression for the current-driven term of the plasma potential energy.

Keywords

heliotron, reduced MHD, resistive mode, current-driven mode, non-resonant mode

DOI: 10.1585/pfr.5.021

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This paper may be cited as follows:

Goshi YAMADA, Yuji NAKAMURA and Katsumi KONDO, Plasma Fusion Res. 5, 021 (2010).