Fast modeling of turbulent transport in fusion plasmas using neural networks

Autor: F. J. Casson, Victor I. Dagnelie, Jet Contributors, Federico Felici, Yann Camenen, Clarisse Bourdelle, Simon Van Mulders, A. Ho, Jonathan Citrin, Karel Lucas van de Plassche
Přispěvatelé: Dutch Institute for Fundamental Energy Research [Eindhoven] (DIFFER), Association EURATOM-CEA (CEA/DSM/DRFC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Eindhoven University of Technology [Eindhoven] (TU/e), Joint European Torus (JET-EFDA), Culham Science Centre [Abingdon], Control Systems Technology, Science and Technology of Nuclear Fusion, Camenen, Yann
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Physics of Plasmas
Physics of Plasmas, 2020
Physics of Plasmas, 27(2):022310. American Institute of Physics
Physics of Plasmas, 27, 022310
Physics of Plasmas, American Institute of Physics, 2020
HAL
ISSN: 1089-7674
1070-664X
DOI: 10.1063/1.5134126
Popis: We present an ultrafast neural network (NN) model, QLKNN, which predicts core tokamak transport heat and particle fluxes. QLKNN is a surrogate model based on a database of 300 million flux calculations of the quasilinear gyrokinetic transport model QuaLiKiz. The database covers a wide range of realistic tokamak core parameters. Physical features such as the existence of a critical gradient for the onset of turbulent transport were integrated into the neural network training methodology. We have coupled QLKNN to the tokamak modelling framework JINTRAC and rapid control-oriented tokamak transport solver RAPTOR. The coupled frameworks are demonstrated and validated through application to three JET shots covering a representative spread of H-mode operating space, predicting turbulent transport of energy and particles in the plasma core. JINTRAC-QLKNN and RAPTOR-QLKNN are able to accurately reproduce JINTRAC-QuaLiKiz T i,e and n e profiles, but 3 to 5 orders of magnitude faster. Simulations which take hours are reduced down to only a few tens of seconds. The discrepancy in the final source-driven predicted profiles between QLKNN and QuaLiKiz is on the order 1%-15%. Also the dynamic behaviour was well captured by QLKNN, with differences of only 4%-10% compared to JINTRAC-QuaLiKiz observed at mid-radius, for a study of density buildup following the L-H transition. Deployment of neural network surrogate models in multi-physics integrated tokamak modelling is a promising route towards enabling accurate and fast tokamak scenario optimization, Uncertainty Quantification, and control applications.
18 pages, 11 figures, Physics of Plasmas, ICDDPS 2019 conference paper
Databáze: OpenAIRE