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Role of Zonal Flow in Turbulent Transport Scaling.

DE2001768652

Publication Date	2000
Personal Author	Lin, Z.; Hahm, T. S.; Krommes, J. A.; Lee, W. W.; Lewandowski, J.; Mynick, H.; Qin, H.; Rewoldt, G.; Tang, W. M.; White, R.
Page Count	11
Abstract	Transport scalings with respect to collisionality n(sup star) and device size r(sup star) 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.
Keywords	Zonal flows Turbulence Damping Fluctuations Iaea Italy Nuclear energy Simulation Spectra Thermonuclear reactors Transport Transport theories
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Princeton Univ., NJ. Plasma Physics Lab.; Department of Energy, Washington, DC.
Document Type	Conference Proceedings
NTIS Issue Number	200123
Contract Number	AC02-76CH03073

Role of Zonal Flow in Turbulent Transport Scaling.

Role of Zonal Flow in Turbulent Transport Scaling.
DE2001768652

Publication Date	2000
Personal Author	Lin, Z.; Hahm, T. S.; Krommes, J. A.; Lee, W. W.; Lewandowski, J.; Mynick, H.; Qin, H.; Rewoldt, G.; Tang, W. M.; White, R.
Page Count	11
Abstract	Transport scalings with respect to collisionality n(sup star) and device size r(sup star) 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.
Keywords	Zonal flows Turbulence Damping Fluctuations Iaea Italy Nuclear energy Simulation Spectra Thermonuclear reactors Transport Transport theories
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Princeton Univ., NJ. Plasma Physics Lab.; Department of Energy, Washington, DC.
Document Type	Conference Proceedings
NTIS Issue Number	200123
Contract Number	AC02-76CH03073