The role of toroidal rotation in the very high energy confinement quality observed in super H-mode experiments on DIII-D
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21ja075_full.pdf
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Author(s)
Ding, S.
Garofalo, A.M.
Jian, X.
Holland, C.
Grierson, B.A.
Soloman, W.M.
Marinoni, Alessandro
Knolker, M.
McClenaghan, J.
Date Issued
June 2021
Journal
Physics of Plasmas
Publisher
AIP
Abstract
In this paper, we report the key role that toroidal rotation and the related ExB shear physics played in the very high energy confinement quality (H98y2>1.5) of super H-mode experiments on DIII-D. Experiments show that the energy confinement quality decreases when toroidal rotation decreases due to the decreased externally controlled torque per particle. Meanwhile, the total pedestal pressure in the experiments remains very high during the rotation and confinement quality change. TGYRO transport modeling suggests the contribution from rotation in the ExB shear is responsible for the confinement quality in excess of standard H-mode (H98y2~1). CGYRO gyrokinetic simulations reveal the governing physics in the core plasma of super H-modes: significant up-shift of nonlinear the ITG critical gradient is observed when applying ExB shear physics in the modeling based on experimental data. The effects of other physical parameters and contribution from pedestal height, which may play minor roles in this study, are also discussed.
Description
Submitted for publication in Physics of Plasmas
MIT Department
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1063/5.0061786
