Plasma and Fusion Research

Volume 17, 2403030 (2022)

Regular Articles

Relations among Turbulent Fluctuations, Zonal Flows, and Transport Coefficients in Time Series Data of Gyrokinetic Simulations
Kotaro FUJII1) and Masanori NUNAMI1,2)
Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
(Received 10 January 2022 / Accepted 24 February 2022 / Published 13 May 2022)


The relations among turbulent amplitude, zonal-flow amplitude, and transport level are discussed for the time series data of nonlinear gyrokinetic simulations for magnetized toroidal plasmas. Since it was shown that the transport coefficient can be expressed as a function of the time-averaged turbulent fluctuation level and the zonal flow amplitude [M. Nunami et al., Phys. Plasmas 20, 092307 (2013)], we apply the results to a model function for the turbulent plasma transport coefficient to extend to a functional relation which includes not the time-averaged data but the time-series data of gyrokinetic simulations. We obtain a new functional relation to the turbulent fluctuations, the zonal-flow amplitudes, and the transport coefficients as a function of the input parameters of the gyrokinetic simulations such as plasma temperature gradients. It is also confirmed that the obtained functional relation can reduce relative error which is compared with the original function with time-averages.


turbulent transport, transport model, gyrokinetic simulation

DOI: 10.1585/pfr.17.2403030


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