| IAEA-CN/TH/P2-8 Electron Transport Driven by Short Wavelength Trapped Electron Mode Turbulence (2008) | |||||||||||||
Abstract | |||||||||||||
| This paper reports progress on gyrokinetic particle simulation of turbulence in fusion plasmas including: (1) Electron transport driven by short wavelength trapped electron mode turbulence; (2) Convergence studies and physics progress in long time simulation of electron temperature gradient turbulence; (3) Electromagnetic simulation of global magnetohydrodynamic modes and finite-β stabilization of the ion temperature gradient mode; and (4) compressible magnetic fluctuation in high-β plasmas driven by anisotropic temperature (mirror mode). I. Electron transport driven by short wavelength trapped electron mode turbulence An outstanding issue in tokamak confinement studies is the origin of the anomalous electron thermal transport in internal transport barriers (ITB), where the ion transport is reduced to the neoclassical level. As the density gradient steepens in barrier regions, the electrostatic trapped electron mode (TEM) is often driven unstable, e.g., in ASDEX Upgrade 1 and JT-60U 2 experiments. The key issue is whether TEM turbulence is capable of driving a large electron heat flux without driving significant ion heat and particle fluxes. In global gyrokinetic particle simulations using the GTC code 3, we find that the TEM is the dominant instability when ηi (ratio of the ion temperature gradient to the density gradient) is small. The TEM modes have a | |||||||||||||
Details der Publikation | |||||||||||||
| |||||||||||||