Constructing Integrable High-pressure Full-current Free-boundary Stellarator Magnetohydrodynamic Equilibrium Solutions

Technical Report · Mon Sep 15 04:00:00 EDT 2003

DOI:https://doi.org/10.2172/815091· OSTI ID:815091

Hudson, S R ^[1]; Monticello, D A; Reiman, A H; Strickler, D J; Hirshman, S P; Ku, L-P; Lazarus, E; Brooks, A; Zarnstorff, M C; Boozer, A H; Fu, G-Y; Neilson, and G.H.

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1. Princeton Plasma Physics Laboratory

For the (non-axisymmetric) stellarator class of plasma confinement devices to be feasible candidates for fusion power stations it is essential that, to a good approximation, the magnetic field lines lie on nested flux surfaces; however, the inherent lack of a continuous symmetry implies that magnetic islands responsible for breaking the smooth topology of the flux surfaces are guaranteed to exist. Thus, the suppression of magnetic islands is a critical issue for stellarator design, particularly for small aspect ratio devices. Pfirsch-Schluter currents, diamagnetic currents, and resonant coil fields contribute to the formation of magnetic islands, and the challenge is to design the plasma and coils such that these effects cancel. Magnetic islands in free-boundary high-pressure full-current stellarator magnetohydrodynamic equilibria are suppressed using a procedure based on the Princeton Iterative Equilibrium Solver [Reiman and Greenside, Comp. Phys. Comm. 43 (1986) 157] which iterate s the equilibrium equations to obtain the plasma equilibrium. At each iteration, changes to a Fourier representation of the coil geometry are made to cancel resonant fields produced by the plasma. The changes are constrained to preserve certain measures of engineering acceptability and to preserve the stability of ideal kink modes. As the iterations continue, the coil geometry and the plasma simultaneously converge to an equilibrium in which the island content is negligible, the plasma is stable to ideal kink modes, and the coils satisfy engineering constraints. The method is applied to a candidate plasma and coil design for the National Compact Stellarator Experiment [Reiman, et al., Phys. Plasmas 8 (May 2001) 2083].

• Research Organization: Princeton Plasma Physics Lab., Princeton, NJ (US)
• Sponsoring Organization: USDOE Office of Science (SC) (US)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 815091
• Report Number(s): PPPL-3867
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ASPECT RATIO
DESIGN
EQUILIBRIUM
MHD -- TOROIDAL
GEOMETRY
MAGNETIC FIELDS
MAGNETIC ISLANDS
MAGNETIC ISLANDS
STABILITY
IDEAL HYDROMAGNETIC
MAGNETIC SURFACES
MAGNETOHYDRODYNAMICS
PLASMA
PLASMA CONFINEMENT
STABILITY
STELLARATORS
SYMMETRY
TOPOLOGY