Intrinsic Toroidal Rotation Driven by Turbulent and Neoclassical Processes in Tokamak Plasmas from Global Gyrokinetic Simulations
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Summary
This summary is machine-generated.Turbulent E×B motion is not the only driver of toroidal rotation in tokamak plasmas. New research shows that drift-orbit and E×B momentum fluxes significantly contribute to residual stress, impacting plasma rotation.
Area Of Science
- Plasma Physics
- Fusion Energy Research
- Computational Physics
Background
- Tokamak plasmas exhibit intrinsic toroidal rotation, crucial for fusion energy.
- Residual stress is a key driver of this rotation.
- Previous studies often neglected contributions from drift-orbit and E×B motion.
Purpose Of The Study
- Investigate the contributions of parallel-momentum flux from drift-orbit motion (Π∥D) and E×B-momentum flux (ΠE×B) to residual stress.
- Analyze these contributions in both the core and edge of a DIII-D H-mode plasma.
- Clarify the mechanisms driving these fluxes.
Main Methods
- Utilized the global total-f gyrokinetic code XGC for simulations.
- Employed a recently developed "orbit-flux" formulation.
- Analyzed plasma behavior in the core and edge regions of a DIII-D H-mode plasma.
Main Results
- Both Π∥D and ΠE×B constitute significant portions of the residual stress.
- In the core, Π∥D exceeds neoclassical levels due to turbulence.
- In the edge, Π∥D represents a countercurrent momentum outflux, primarily from ion orbit loss, even without turbulence.
Conclusions
- Drift-orbit (Π∥D) and E×B (ΠE×B) momentum fluxes are critical components of residual stress in tokamak plasmas.
- Turbulence drives higher-than-neoclassical Π∥D in the core.
- Collisional ion orbit loss is the main driver of edge Π∥D, highlighting the importance of these fluxes for intrinsic toroidal rotation studies.
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