Optimized finite-build stellarator coils using automatic differentiation
| Autor: | Caoxiang Zhu, Stuart R. Hudson, Nick McGreivy |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
Nuclear and High Energy Physics Quantitative Biology::Biomolecules Automatic differentiation Physics::Medical Physics FOS: Physical sciences Free space Computational Physics (physics.comp-ph) Condensed Matter Physics Space (mathematics) Topology 01 natural sciences Physics - Plasma Physics 010305 fluids & plasmas law.invention Plasma Physics (physics.plasm-ph) law Position (vector) Electromagnetic coil Orientation (geometry) 0103 physical sciences 010306 general physics Physics - Computational Physics Fourier series Stellarator |
| DOI: | 10.48550/arxiv.2009.00196 |
| Popis: | A new stellarator coil design code is introduced that optimizes the position and winding pack orientation of finite-build coils. The new code, called flexible optimized curves in space using automatic differentiation (AD) and finite build (FOCUSADD), performs gradient-based optimization in a high-dimensional, non-convex space. The derivatives with respect to parameters of finite-build coils are easily and efficiently computed using AD. FOCUSADD parametrizes coil positions in free space using a Fourier series and uses a multi-filament approximation to the coil winding pack. The orientation of the winding pack is parametrized with a Fourier series and can be optimized as well. Optimized finite-build coils for a Wendelstein 7-X (W7-X)-like stellarator are found, and compared with filamentary coil results. The final positions of optimized finite-build W7-X-like coils are shifted, on average, by approximately 2.5 mm relative to optimized filamentary coils. These results suggest that finite-build effects should be accounted for in the optimization of stellarators with low coil tolerances. |
| Databáze: | OpenAIRE |
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