New method to design stellarator coils without the winding surface

Abstract

Finding an easy-to-build coils set has been a critical issue for stellarator design for decades. Conventional approaches assume a toroidal "winding" surface. We'll investigate if the existence of winding surface unnecessarily constrains the optimization, and a new method to design coils for stellarators is presented. Each discrete coil is represented as an arbitrary, closed, one-dimensional curve embedded in three-dimensional space. A target function to be minimized that covers both physical requirements and engineering constraints is constructed. The derivatives of the target function are calculated analytically. A numerical code, named FOCUS, has been developed. Applications to a simple configuration, the W7-X, and LHD plasmas are presented.

25 pages, 11 figures, submitted to Nuclear Fusion on May 24

References in corpus (1)

• An improved current potential method for fast computation of stellarator coil shapes

Cited by in corpus (34)

• Direct construction of optimized stellarator shapes. II. Numerical quasisymmetric solutions
• Single-stage gradient-based stellarator coil design: stochastic optimization
• Single-Stage Stellarator Optimization: Combining Coils with Fixed Boundary Equilibria
• Combined plasma-coil optimization algorithms
• Designing stellarators using perpendicular permanent magnets
• Direct stellarator coil design using global optimization: application to a comprehensive exploration of quasi-axisymmetric devices
• Identification of important error fields in stellarators using Hessian matrix method
• Direct computation of magnetic surfaces in Boozer coordinates and coil optimization for quasi-symmetry
• Optimized finite-build stellarator coils using automatic differentiation
• Permanent magnet optimization for stellarators as sparse regression
• Calculation of permanent magnet arrangements for stellarators: A linear least-squares method
• Figures of merit for stellarators near the magnetic axis
• Unsupervised Discovery of Inertial-Fusion Plasma Physics using Differentiable Kinetic Simulations and a Maximum Entropy Loss Function
• Greedy permanent magnet optimization
• Non-Planar Coil Winding Angle Optimization for Compatibility with Non-Insulated High-Temperature Superconducting Magnets
• Design of an arrangement of cubic magnets for a quasi-axisymmetric stellarator experiment
• Non-planar elasticae as optimal curves for the magnetic axis of stellarators
• Minimization of magnetic forces on Stellarator coils
• Gradient-based optimization of 3D MHD equilibria
• Stochastic and a posteriori optimization to mitigate coil manufacturing errors in stellarator design
• An Introduction to Stellarators: From magnetic fields to symmetries and optimization
• Global Stochastic Optimization of Stellarator Coil Configurations
• Scaling Gaussian Processes with Derivative Information Using Variational Inference
• Existence of an optimized stellarator with simple coils
• Stellarator optimization for nested magnetic surfaces at finite $\beta$ and toroidal current
• Computing the shape gradient of stellarator coil complexity with respect to the plasma boundary
• A neoclassically optimized compact stellarator with four planar coils
• Stellarator coil design using cubic splines for improved access on the outboard side
• Adjoint methods for quasisymmetry of vacuum fields on a surface
• Computation of the Biot-Savart line integral with higher-order convergence using straight segments
• A framework for discrete optimization of stellarator coils
• Topology optimization of permanent magnets for stellarators
• Including the vacuum energy in stellarator coil design
• Efficient Computation of Stellarator Coils with an Augmented Lagrangian Optimization Method