English

Accelerated Bayesian inference of plasma profiles with self-consistent MHD equilibria at W7-X via neural networks

Plasma Physics 2023-11-21 v1

Abstract

High-β\langle \beta \rangle operations require a fast and robust inference of plasma parameters with a self-consistent MHD equilibrium. Precalculated MHD equilibria are usually employed at W7-X due to the high computational cost. To address this, we couple a physics-regularized NN model that approximates the ideal-MHD equilibrium with the Bayesian modeling framework Minerva. We show the fast and robust inference of plasma profiles (electron temperature and density) with a self-consistent MHD equilibrium approximated by the NN model. We investigate the robustness of the inference across diverse synthetic W7-X plasma scenarios. The inferred plasma parameters and their uncertainties are compatible with the parameters inferred using the VMEC, and the inference time is reduced by more than two orders of magnitude. This work suggests that MHD self-consistent inferences of plasma parameters can be performed between shots.

Keywords

Cite

@article{arxiv.2305.12889,
  title  = {Accelerated Bayesian inference of plasma profiles with self-consistent MHD equilibria at W7-X via neural networks},
  author = {Andrea Merlo and Andrea Pavone and Daniel Böckenhoff and Ekkehard Pasch and Golo Fuchert and Kai Jakob Brunner and Kian Rahbarnia and Jonathan Schilling and Udo Höfel and Sehyun Kwak and Jakob Svensson and Thomas Sunn Pedersen and the W7-X team},
  journal= {arXiv preprint arXiv:2305.12889},
  year   = {2023}
}

Comments

18 pages, 6 figures