Geometry dependence of the fluctuation intensity in gyrokinetic turbulence. (27th November 2020)

• Record Type: Journal Article
• Authors: Staebler, G M; Candy, J; Belli, E A; Kinsey, J E; Bonanomi, N; Patel, B
• Is Part Of: Plasma physics and controlled fusion. Volume 63:Number 1(2021)
• Publication Date: 2020-11-27
• Subjects: tokamak transport -- quasi-linear model -- gyrokinetic turbulence; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/1361-6587/abc861
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: The findings of an investigation into the properties of the three dimensional (3D) saturated fluctuation intensity of the electric potential in gyrokinetic turbulence simulations is presented. Scans in flux surface elongation and Shafranov shift are used to isolate the tokamak geometric dependencies. The potential intensity required in order to compute exact fluxes by a quasilinear method is determined using linear eigenmodes computed with the gyrokinetic code. A model of this non-linear intensity is constructed using the linear eigenmode properties and the geometry shape functions obtained from the 3D intensity spectrum. The model computes the poloidal wavenumber spectrum of the electron and ion energy fluxes with unprecedented accuracy. New insights are gained into the way zonal flow mixing saturates ion-scale turbulence by controlling the radial wavenumber width of the turbulence spectrum.