Diamagnetic drift effects on the lown magnetohydrodynamic modes at the high mode pedestal with plasma rotation
Abstract
The diamagnetic drift effects on the lown magnetohydrodynamic instabilities at the highmode (Hmode) pedestal are investigated in this paper with the inclusion of bootstrap current for equilibrium and rotation effects for stability, where n is the toroidal mode number. The AEGIS (Adaptive EiGenfunction Independent Solutions) code [L. J. Zheng and M. T. Kotschenreuther, J. Comp. Phys. 211 (2006)] is extended to include the diamagnetic drift effects. This can be viewed as the lowest order approximation of the finite Larmor radius effects in consideration of the pressure gradient steepness at the pedestal. The Hmode discharges at Jointed European Torus is reconstructed numerically using the VMEC code [P. Hirshman and J. C. Whitson, Phys. Fluids 26, 3553 (1983)], with bootstrap current taken into account. Generally speaking, the diamagnetic drift effects are stabilizing. Our results show that the effectiveness of diamagnetic stabilization depends sensitively on the safe factor value (q{sub s}) at the safetyfactor reversal or plateau region. The diamagnetic stabilization are weaker, when q{sub s} is larger than an integer; while stronger, when q{sub s} is smaller or less larger than an integer. We also find that the diamagnetic drift effects also depend sensitively on the rotation direction. The diamagnetic stabilization inmore »
 Authors:

 Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)
 Publication Date:
 OSTI Identifier:
 22304240
 Resource Type:
 Journal Article
 Journal Name:
 Physics of Plasmas
 Additional Journal Information:
 Journal Volume: 21; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070664X
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOOTSTRAP CURRENT; EIGENFUNCTIONS; HMODE PLASMA CONFINEMENT; JET TOKAMAK; LARMOR RADIUS; MATHEMATICAL SOLUTIONS; PLASMA; PRESSURE GRADIENTS; SAFETY; STABILITY; STABILIZATION
Citation Formats
Zheng, L. J., Kotschenreuther, M. T., and Valanju, P. Diamagnetic drift effects on the lown magnetohydrodynamic modes at the high mode pedestal with plasma rotation. United States: N. p., 2014.
Web. doi:10.1063/1.4881470.
Zheng, L. J., Kotschenreuther, M. T., & Valanju, P. Diamagnetic drift effects on the lown magnetohydrodynamic modes at the high mode pedestal with plasma rotation. United States. doi:10.1063/1.4881470.
Zheng, L. J., Kotschenreuther, M. T., and Valanju, P. Sun .
"Diamagnetic drift effects on the lown magnetohydrodynamic modes at the high mode pedestal with plasma rotation". United States. doi:10.1063/1.4881470.
@article{osti_22304240,
title = {Diamagnetic drift effects on the lown magnetohydrodynamic modes at the high mode pedestal with plasma rotation},
author = {Zheng, L. J. and Kotschenreuther, M. T. and Valanju, P.},
abstractNote = {The diamagnetic drift effects on the lown magnetohydrodynamic instabilities at the highmode (Hmode) pedestal are investigated in this paper with the inclusion of bootstrap current for equilibrium and rotation effects for stability, where n is the toroidal mode number. The AEGIS (Adaptive EiGenfunction Independent Solutions) code [L. J. Zheng and M. T. Kotschenreuther, J. Comp. Phys. 211 (2006)] is extended to include the diamagnetic drift effects. This can be viewed as the lowest order approximation of the finite Larmor radius effects in consideration of the pressure gradient steepness at the pedestal. The Hmode discharges at Jointed European Torus is reconstructed numerically using the VMEC code [P. Hirshman and J. C. Whitson, Phys. Fluids 26, 3553 (1983)], with bootstrap current taken into account. Generally speaking, the diamagnetic drift effects are stabilizing. Our results show that the effectiveness of diamagnetic stabilization depends sensitively on the safe factor value (q{sub s}) at the safetyfactor reversal or plateau region. The diamagnetic stabilization are weaker, when q{sub s} is larger than an integer; while stronger, when q{sub s} is smaller or less larger than an integer. We also find that the diamagnetic drift effects also depend sensitively on the rotation direction. The diamagnetic stabilization in the corotation case is stronger than in the counter rotation case with respect to the ion diamagnetic drift direction.},
doi = {10.1063/1.4881470},
journal = {Physics of Plasmas},
issn = {1070664X},
number = 6,
volume = 21,
place = {United States},
year = {2014},
month = {6}
}