Role of Zonal Flow in Turbulent Transport Scaling
Transport scalings with respect to collisionality (n*) and device size (r*) are obtained from massively parallel gyrokinetic particle simulations of toroidal ion-temperature-gradient (ITG) turbulence in the presence of zonal flows. Simulation results show that ion thermal transport from electrostatic ITG turbulence depends on ion-ion collisions due to the neo-classical damping of self-generated EXB zonal flows that regulate the turbulence. Fluctuations and heat transport levels exhibit bursting behavior with a period corresponding to the collisional damping time of poloidal flows. Results from large-scale full torus simulations with device-size scans for realistic parameters show that Bohm-like transport can be driven by microscopic scale fluctuations in the ITG turbulence with isotropic spectra. These simulation results resolve some apparent physics contradictions between experimental observations and turbulent transport theories.
- Research Organization:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 768652
- Report Number(s):
- PPPL-3508; TRN: US0005776
- Resource Relation:
- Conference: 18th International Atomic Energy Agency's (IAEA) Fusion Energy Conference (FEC-2000), Sorrento (IT), 10/04/2000--10/10/2000; Other Information: PBD: 15 Nov 2000
- Country of Publication:
- United States
- Language:
- English
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