Plasma and Fusion Research

Volume 7, 2403032 (2012)

Regular Articles

Numerical Calculation of MHD Equilibria including Static Magnetic Islands in a Straight Heliotron Configuration by Means of a Field Line Tracing Method

Kinya SAITO¹⁾, Katsuji ICHIGUCHI^1,2) and Ryuichi ISHIZAKI^1,2)

1): The Graduate University for Advanced Studies, Toki 509-5292, Japan
2): National Institute for Fusion Science, Toki 509-5292, Japan

(Received 6 December 2011 / Accepted 4 March 2012 / Published 10 May 2012)

Abstract

Magnetohydrodynamics (MHD) equilibria including static magnetic islands for the reduced MHD equations in a straight heliotron plasma are calculated. The equilibria are obtained as the solution of the coupled equations of the constant pressure along each field line and the force balance. The former and the latter equations are solved by means of a field line tracing method and a relaxation method, respectively. There exist two kinds of solutions. One is the equilibrium of which the pressure profile is flat at the O-point and steep at the X-point. In this case, the pressure gradient is discontinuous at the separatrix of the magnetic island. The other is the equilibrium of which the pressure profile is flat at not only the O-point but also the X-point. In the case, the pressure gradient is continuous at the separatrix.

Keywords

heliotron, MHD equilibrium, static magnetic island, field line tracing, separatrix

DOI: 10.1585/pfr.7.2403032

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This paper may be cited as follows:

Kinya SAITO, Katsuji ICHIGUCHI and Ryuichi ISHIZAKI, Plasma Fusion Res. 7, 2403032 (2012).