Plasma and Fusion Research

Volume 16, 2403016 (2021)

Regular Articles

Application of the Ensemble Kalman Smoother to Turbulent Transport Analysis in LHD Plasma
Yuya MORISHITA, Sadayoshi MURAKAMI, Masayuki YOKOYAMA1,3) and Genta UENO2,3,4)
Department of Nuclear Engineering, Kyoto University, Kyoto 615-8540, Japan
1)
National Institute for Fusion Science, Toki 509-5292, Japan
2)
The Institute of Statistical Mathematics, Tokyo 190-8562, Japan
3)
The Graduate University for Advanced Studies, SOKENDAI, Toki 509-5292 and Tokyo 190-8562, Japan
4)
The Joint Support-Center for Data Science Research, Tokyo 190-0014, Japan
(Received 15 November 2020 / Accepted 21 December 2020 / Published 10 February 2021)

Abstract

The ensemble Kalman smoother (EnKS) is introduced to the data assimilation system, ASTI, based on the integrated transport simulation code, TASK3D. We use the EnKS to estimate state variables composed of electron and ion temperature, density, and numerical factors of turbulent transport models and neutral beam injection (NBI) heat deposition. The time series data of plasma temperature and density profiles are assimilated into TASK3D. The estimation performance of the EnKS is investigated, and the EnKS is applied to an NBI plasma in the Large Helical Device (LHD) (shot:114053) to estimate the factors of the turbulent heat transport model. The obtained factors can reproduce the experimental temperature data with high accuracy. These results indicate the effectiveness and validity of the EnKS approach for accurate estimation of fusion plasma parameters.

Keywords

data assimilation, ASTI, ensemble Kalman smoother, TASK3D, LHD

DOI: 10.1585/pfr.16.2403016

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