Details

Autor(en) / Beteiligte

• Nakayama, T
• Nakata, M
• Honda, M
• Nunami, M
• Matsuoka, S

Titel

Nonlinear functional relation covering near- and far-marginal stability in ion temperature gradient driven turbulence

Ist Teil von

• Plasma physics and controlled fusion, 2022-07, Vol.64 (7), p.75007

Ort / Verlag

IOP Publishing

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Abstract A novel nonlinear functional relation of turbulence potential intensity, zonal flow potential intensity, and ion thermal diffusivity that accurately reproduces nonlinear gyrokinetic simulations of toroidal ion temperature gradient (ITG) driven turbulence is proposed. Applying mathematical optimization techniques to find extremal solutions in high-dimensional parameter space, the optimal regression parameters in the functional form are determined to be valid for both near- and far-marginal regime of the ITG stability including the Dimits-shift. Then, the regression error of ∼5% is accomplished. In addition, it is clarified that the intensity ratio of the zonal flow and turbulence potential intensity is a crucial factor to determine the reproduction accuracy.