Impact of E × B shear flow on low-n MHD instabilities
Abstract
Recently, the stationary high confinement operations with improved pedestal conditions have been achieved in DIII-D [K. H. Burrell et al., Phys. Plasmas 23, 056103 (2016)], accompanying the spontaneous transition from the coherent edge harmonic oscillation (EHO) to the broadband MHD turbulence state by reducing the neutral beam injection torque to zero. It is crucial for the burning plasma devices such as ITER. Simulations about the effects of E×B shear flow on the quiescent H-mode (QH-mode) are carried out using the three-field two-fluid model in the field-aligned coordinate under the BOUT++ framework. Using the shifted circular cross-section equilibriums including bootstrap current, the results demonstrate that the E×B shear flow strongly destabilizes low-n peeling modes, which are mainly driven by the gradient of parallel current in peeling-dominant cases and are sensitive to the Er shear. Adopting the much more general shape of E×B shear (ωE=Er/RBθ) profiles, the linear and nonlinear BOUT++ simulations show qualitative consistence with the experiments. The stronger shear flow shifts the most unstable mode to lower-n and narrows the mode spectrum. At the meantime, the nonlinear simulations of the QH-mode indicate that the shear flow in both co- and counter directions of diamagnetic flow has some similar effects. Themore »
- Authors:
-
[2];
[4];
- Peking Univ., Beijing (China). School of Physics, State Key Lab. of Nuclear Physics
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Peking Univ., Beijing (China). School of Physics, State Key Lab. of Nuclear Physics; Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chinese Academy of Sciences (CAS), Hefei (China). Inst. of Plasma Physics
- Publication Date:
- Research Org.:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA)
- OSTI Identifier:
- 1566033
- Alternate Identifier(s):
- OSTI ID: 1375646
- Report Number(s):
- LLNL-JRNL-721760
Journal ID: ISSN 1070-664X; 868466; TRN: US2000963
- Grant/Contract Number:
- AC52-07NA27344; AC52-7NA27344
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Volume: 24; Journal Issue: 5; Journal ID: ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Citation Formats
Chen, J. G., Xu, X. Q., Ma, C. H., Xi, P. W., Kong, D. F., and Lei, Y. A. Impact of E × B shear flow on low-n MHD instabilities. United States: N. p., 2017.
Web. doi:10.1063/1.4984257.
Chen, J. G., Xu, X. Q., Ma, C. H., Xi, P. W., Kong, D. F., & Lei, Y. A. Impact of E × B shear flow on low-n MHD instabilities. United States. https://doi.org/10.1063/1.4984257
Chen, J. G., Xu, X. Q., Ma, C. H., Xi, P. W., Kong, D. F., and Lei, Y. A. Wed .
"Impact of E × B shear flow on low-n MHD instabilities". United States. https://doi.org/10.1063/1.4984257. https://www.osti.gov/servlets/purl/1566033.
@article{osti_1566033,
title = {Impact of E × B shear flow on low-n MHD instabilities},
author = {Chen, J. G. and Xu, X. Q. and Ma, C. H. and Xi, P. W. and Kong, D. F. and Lei, Y. A.},
abstractNote = {Recently, the stationary high confinement operations with improved pedestal conditions have been achieved in DIII-D [K. H. Burrell et al., Phys. Plasmas 23, 056103 (2016)], accompanying the spontaneous transition from the coherent edge harmonic oscillation (EHO) to the broadband MHD turbulence state by reducing the neutral beam injection torque to zero. It is crucial for the burning plasma devices such as ITER. Simulations about the effects of E×B shear flow on the quiescent H-mode (QH-mode) are carried out using the three-field two-fluid model in the field-aligned coordinate under the BOUT++ framework. Using the shifted circular cross-section equilibriums including bootstrap current, the results demonstrate that the E×B shear flow strongly destabilizes low-n peeling modes, which are mainly driven by the gradient of parallel current in peeling-dominant cases and are sensitive to the Er shear. Adopting the much more general shape of E×B shear (ωE=Er/RBθ) profiles, the linear and nonlinear BOUT++ simulations show qualitative consistence with the experiments. The stronger shear flow shifts the most unstable mode to lower-n and narrows the mode spectrum. At the meantime, the nonlinear simulations of the QH-mode indicate that the shear flow in both co- and counter directions of diamagnetic flow has some similar effects. The nonlinear mode interaction is enhanced during the mode amplitude saturation phase. These findings reveal that the fundamental physics mechanism of the QH-mode may be shear flow and are significant for understanding the mechanism of EHO and QH-mode.},
doi = {10.1063/1.4984257},
journal = {Physics of Plasmas},
number = 5,
volume = 24,
place = {United States},
year = {Wed May 24 00:00:00 EDT 2017},
month = {Wed May 24 00:00:00 EDT 2017}
}
Free Publicly Available Full Text
Publisher's Version of Record
Other availability
Search WorldCat to find libraries that may hold this journal
Cited by: 19 works
Citation information provided by
Web of Science
Web of Science
Figures / Tables:
FIG. 1: Two serials of equilibrium profiles in JET-like Tokamak geometry including bootstrap current with shifted circular cross-section used in this paper. The colored solid lines and black dashed lines represent the current and pressure profiles respectively. The equilibrium serial 1 has same pressure profile but different density and currentmore »
All figures and tables
(8 total)
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.
Works referenced in this record:
Energy loss for grassy ELMs and effects of plasma rotation on the ELM characteristics in JT-60U
journal, July 2005
- Oyama, N.; Sakamoto, Y.; Isayama, A.
- Nuclear Fusion, Vol. 45, Issue 8
Quiescent H-Mode Plasmas with Strong Edge Rotation in the Cocurrent Direction
journal, April 2009
- Burrell, K. H.; Osborne, T. H.; Snyder, P. B.
- Physical Review Letters, Vol. 102, Issue 15
Nonlinear MHD simulations of Quiescent H-mode plasmas in DIII-D
journal, September 2015
- Liu, F.; Huijsmans, G. T. A.; Loarte, A.
- Nuclear Fusion, Vol. 55, Issue 11
Influence of equilibrium shear flow on peeling-ballooning instability and edge localized mode crash
journal, September 2012
- Xi, P. W.; Xu, X. Q.; Wang, X. G.
- Physics of Plasmas, Vol. 19, Issue 9
Nonlinear Simulations of Peeling-Ballooning Modes with Anomalous Electron Viscosity and their Role in Edge Localized Mode Crashes
journal, October 2010
- Xu, X. Q.; Dudson, B.; Snyder, P. B.
- Physical Review Letters, Vol. 105, Issue 17
Edge-localized-modes in tokamaks
journal, September 2014
- Leonard, A. W.
- Physics of Plasmas, Vol. 21, Issue 9
Impact of a large density gradient on linear and nonlinear edge-localized mode simulations
journal, September 2013
- Xi, P. W.; Xu, X. Q.; Xia, T. Y.
- Nuclear Fusion, Vol. 53, Issue 11
The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmasa)
journal, May 2015
- Garofalo, A. M.; Burrell, K. H.; Eldon, D.
- Physics of Plasmas, Vol. 22, Issue 5
Impact of toroidal rotation on ELM behaviour in the H-mode on JT-60U
journal, April 2004
- Sakamoto, Y.; Shirai, H.; Fujita, T.
- Plasma Physics and Controlled Fusion, Vol. 46, Issue 5A
Digital Bispectral Analysis and Its Applications to Nonlinear Wave Interactions
journal, January 1979
- Kim, Young C.; Powers, Edward J.
- IEEE Transactions on Plasma Science, Vol. 7, Issue 2
NIMROD modeling of quiescent H-mode: reconstruction considerations and saturation mechanism
journal, September 2016
- King, J. R.; Burrell, K. H.; Garofalo, A. M.
- Nuclear Fusion, Vol. 57, Issue 2
Rotational shear effects on edge harmonic oscillations in DIII-D quiescent H-mode discharges
journal, June 2016
- Chen, Xi; Burrell, K. H.; Ferraro, N. M.
- Nuclear Fusion, Vol. 56, Issue 7
Investigation of pellet-triggered MHD events in ASDEX Upgrade and JET
journal, August 2008
- Lang, P. T.; Lackner, K.; Maraschek, M.
- Nuclear Fusion, Vol. 48, Issue 9
Reactor-relevant quiescent H-mode operation using torque from non-axisymmetric, non-resonant magnetic fields
journal, May 2012
- Burrell, K. H.; Garofalo, A. M.; Solomon, W. M.
- Physics of Plasmas, Vol. 19, Issue 5
Stability and dynamics of the edge pedestal in the low collisionality regime: physics mechanisms for steady-state ELM-free operation
journal, August 2007
- Snyder, P. B.; Burrell, K. H.; Wilson, H. R.
- Nuclear Fusion, Vol. 47, Issue 8
Advances in understanding quiescent H-mode plasmas in DIII-D
journal, May 2005
- Burrell, K. H.; West, W. P.; Doyle, E. J.
- Physics of Plasmas, Vol. 12, Issue 5
Effects of E×B velocity shear and magnetic shear on turbulence and transport in magnetic confinement devices
journal, May 1997
- Burrell, K. H.
- Physics of Plasmas, Vol. 4, Issue 5
Studies of the ‘Quiescent H-mode’ regime in ASDEX Upgrade and JET
journal, July 2005
- Suttrop, W.; Hynönen, V.; Kurki-Suonio, T.
- Nuclear Fusion, Vol. 45, Issue 7
Erratum: “Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime” [Phys. Plasmas 6 , 2834 (1999)]
journal, December 2002
- Sauter, O.; Angioni, C.; Lin-Liu, Y. R.
- Physics of Plasmas, Vol. 9, Issue 12
3D vacuum magnetic field modelling of the ITER ELM control coil during standard operating scenarios
journal, August 2013
- Evans, T. E.; Orlov, D. M.; Wingen, A.
- Nuclear Fusion, Vol. 53, Issue 9
Edge localized modes and the pedestal: A model based on coupled peeling–ballooning modes
journal, May 2002
- Snyder, P. B.; Wilson, H. R.; Ferron, J. R.
- Physics of Plasmas, Vol. 9, Issue 5
Boundary plasma turbulence simulations for tokamaks
journal, January 2014
- . Xu, X. Q.; Umansky, M. V.; Dudson, B.
- Communications in Computational Physics
Discovery of stationary operation of quiescent H-mode plasmas with net-zero neutral beam injection torque and high energy confinement on DIII-D
journal, March 2016
- Burrell, K. H.; Barada, K.; Chen, X.
- Physics of Plasmas, Vol. 23, Issue 5
Works referencing / citing this record:
Progress towards modeling tokamak boundary plasma turbulence and understanding its role in setting divertor heat flux widths
journal, May 2018
- Chen, B.; Xu, X. Q.; Xia, T. Y.
- Physics of Plasmas, Vol. 25, Issue 5
Impact of bootstrap current and Landau-fluid closure on ELM crashes and transport
journal, May 2018
- Chen, J. G.; Xu, X. Q.; Ma, C. H.
- Physics of Plasmas, Vol. 25, Issue 5
Edge state selection by modulating E × B shearing profile in toroidally confined plasmas
journal, May 2019
- Zhang, Y.; Guo, Z. B.; Xu, X. Q.
- Physics of Plasmas, Vol. 26, Issue 5
E × B flow shear mitigates ballooning-driven edge-localized modes at high collisionality: experiment and simulation
journal, December 2018
- Kong, D. F.; Xu, X. Q.; Diamond, P. H.
- Nuclear Fusion, Vol. 59, Issue 1
Figures / Tables found in this record:
Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.