Abstract Details
Abstracts
Author: Hongxuan Zhu
Requested Type: Poster
Submitted: 2023-03-31 09:26:30
Co-authors: T. Stoltzfus-Dueck, R. Hager, S. Ku, C. S. Chang
Contact Info:
Princeton Plasma Physics Laboratory
100 Stellarator Road
Princeton, 08540
USA
Abstract Text:
Understanding intrinsic toroidal rotation is important for future tokamaks like ITER. In gyrokinetic plasmas, the ion gyrocenter toroidal angular momentum can be transported in the radial direction via three processes: turbulent transport of the parallel momentum, neoclassical transport of the parallel momentum, and turbulent transport of the $E times B$ momentum. Theories and conventional delta-f simulations have been mainly focused on the first process based on the ordering assumption. However, global total-f simulations have suggested that the three processes could be on the same order. Here, we study intrinsic toroidal rotation in flux-driven ion-temperature-gradient turbulence using the global total-f gyrokinetic code XGC1. After the turbulence onset, zonal flows quickly form and reach a steady value. Meanwhile, there is a persistent toroidal-rotation acceleration, whose direction correlates with the zonal-flow pattern. Simulation results showed that for the ion gyrocenter particle flux, the turbulent contribution is balanced by the neoclassical contribution, resulting in steady-state zonal flows. However, for the momentum flux, simulations suggested that the turbulent transport of $E times B$ momentum is not balanced by other processes and results in persistent toroidal-rotation acceleration. The correlation between zonal flows and toroidal rotation can be explained as the result of the correlation between turbulent particle and momentum flux.
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