Extending near-axis equilibria in DESC

2025/06/05 by Dario Panici, Eduardo Rodriguez, Panici, Dario +7
Physics and Astronomy · #FOS: Physical sciences #Laser-Plasma Interactions and Diagnostics #Magnetic confinement fusion research #Plasma Physics (physics.plasm-ph) #Solar and Space Plasma Dynamics

paper · pdf · doi:10.48550/arxiv.2506.05170

openalex publication_date 2025/06/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

The near-axis description of optimised stellarator fields has proven to be a powerful tool both for design and understanding of this magnetic confinement concept. The description consists of an asymptotic model of the equilibrium in the distance from its centermost axis, and is thus only approximate. Any practical application therefore requires the eventual construction of a global equilibrium. This paper presents a novel way of constructing global equilibria using the DESC code that guarantees the correct asymptotic behaviour imposed by a given near-axis construction. The theoretical underpinnings of this construction are carefully presented, and benchmarking examples provided. This opens the door to an efficient coupling of the near-axis framework and that of global equilibria for future optimisation efforts.

Citations

• Computing MHD equilibria of stellarators with a flexible coordinate frame
• Near-axis description of stellarator-symmetric quasi-isodynamic stellarators to second order
• A comprehensive exploration of quasisymmetric stellarators and their coil sets
• Helicity of the magnetic axes of quasi-isodynamic stellarators
• Mapping the space of quasisymmetric stellarators using optimized near-axis expansion
• The DESC stellarator code suite Part 3: Quasi-symmetry optimization
• The DESC Stellarator Code Suite Part I: Quick and accurate equilibria computations
• Steepest-descent moment method for three-dimensional magnetohydrodynamic equilibria

Cited by

• Numerical asymptotics of near-axis expansions of quasisymmetric magnetohydrostatic equilibria with anisotropic pressure

Related

• The DESC stellarator code suite. Part 1. Quick and accurate equilibria computations
• The DESC Stellarator Code Suite Part I: Quick and accurate equilibria computations
• Near-axis measures of quasi-isodynamic configurations
• A geometric approach to constructing quasi-isodynamic fields
• Stellarator equilibrium axis-expansion to all orders in distance from the axis for arbitrary plasma beta