Spectrally accurate, reverse-mode differentiable bounce-averaging algorithm and its applications
Abstract
We present a fast, spectrally (exponentially) accurate, automatically differentiable bounce-averaging algorithm that is used to simplify kinetic models. Using this algorithm, implemented in the DESC stellarator optimisation suite, we can perform efficient optimisation of many objectives to improve stellarator performance, such as the effective ripple $\epsilon _{\mathrm{eff}}$ metric for the neoclassical transport coefficient in the low collisionality regime and proxies for energetic particle confinement. For the first time, we optimise a finite-beta stellarator to directly reduce neoclassical ripple transport using reverse-mode differentiation. This ensures the computational cost of differentiation is independent of the number of controllable parameters.
Fields of Study & Subjects
Advanced Adaptive Filtering Techniques
Magnetic Bearings and Levitation Dynamics
Underwater Acoustics Research
Publication details
- Journal / source
- Journal of Plasma Physics
- Publisher
- Cambridge University Press (CUP)
- Volume
- 92
- Issue
- 3
- Publication date
- 1 June 2026
- Language
- EN