[2510.13521] Narrow Operator Models of Stellarator Equilibria in Fourier Zernike Basis

Physics > Plasma Physics arXiv:2510.13521 (physics) [Submitted on 15 Oct 2025 (v1), last revised 28 Mar 2026 (this version, v2)] Title:Narrow Operator Models of Stellarator Equilibria in Fourier Zernike Basis Authors:Timo Thun, Rory Conlin, Dario Panici, Daniel Böckenhoff View a PDF of the paper titled Narrow Operator Models of Stellarator Equilibria in Fourier Zernike Basis, by Timo Thun and 3 other authors View PDF Abstract:Numerical computation of the ideal Magnetohydrodynamic (MHD) equilibrium magnetic field is at the base of stellarator optimisation and provides the starting point for solving more sophisticated Partial Differential Equations (PDEs) like transport or turbulence models. Conventional approaches solve for a single stationary point of the ideal MHD equations, which is fully defined by three invariants and the numerical scheme employed by the solver. We present the first numerical approach that can solve for a continuous distribution of equilibria with fixed boundary and rotational transform, varying only the pressure invariant. This approach minimises the force residual by optimising parameters of multilayer perceptrons (MLP) that map from a scalar pressure multiplier to the Fourier Zernike basis as implemented in the modern stellarator equilibrium solver DESC. Comments: Subjects: Plasma Physics (physics.plasm-ph); Artificial Intelligence (cs.AI); Machine Learning (cs.LG) Cite as: arXiv:2510.13521 [physics.plasm-ph]   (or arXiv:2510.13521v2 [physics.plasm-...