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Implementation of Hamada principle in calculations of nested 3-D equilibria

Part of: PLA Tribute to V D Shafranov: 1929-2014 Focus on Fusion

Published online by Cambridge University Press:  21 December 2015

Leonid E. Zakharov
Leonid E. Zakharov*
Affiliation:
LiWFusion, PO Box 2391, Princeton, NJ 08543, USA
*
†Email address for correspondence: lezprinceton@gmail.com
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Abstract

Plasma confinement is based on the use of nested toroidal magnetic surfaces. In axisymmetric configurations the nestedness is provided by the existence of a flux function describing the magnetic surfaces explicitly. In the case of a three-dimensional magnetic field, the nested surfaces represent an exception. More typically, magnetic islands are formed on the resonant surfaces. The islands could degrade the plasma performance. The rigorous condition for the existence of nested surfaces without islands was formulated by Hamada (Nucl. Fusion, vol. 2, 1962, pp. 23–37) but was not implemented directly into numerical codes used, for example, for designing the stellarator configurations. This paper introduces a method of implementation of the Hamada principle in numerical algorithms. The proposed approach allows for simple linearized equilibrium equations (LEE) and potentially very efficient three-dimensional calculations of nested equilibria.

Type
Research Article
Information
Journal of Plasma Physics , Volume 81 , Issue 6 , December 2015 , 515810609
Copyright
© Cambridge University Press 2015 

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