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Title: Enhanced toroidal flow stabilization of edge localized modes with increased plasma density

Abstract

Toroidal flow alone is generally thought to have an important influence on tokamak edge pedestal stability, even though theoretical analysis often predicts merely a weak stabilizing effect of toroidal flow on the edge localized modes (ELMs) in experimental parameter regimes. For the first time, we find from two-fluid MHD calculations that such a stabilization, however, can be significantly enhanced by increasing the edge plasma density. Our finding resolves a long-standing mystery whether or how toroidal rotation can indeed have an effective influence on ELMs, and explains why the ELM mitigation and suppression by toroidal rotation are more favorably achieved in higher collisionality regime in recent experiments. Furthermore, the finding suggests a new control scheme on modulating toroidal flow stabilization of ELMs with plasma density, along with a new additional constraint on the optimal level of plasma density for the desired edge plasma conditions

Authors:
 [1]; ORCiD logo [2]; ORCiD logo [1]
  1. Univ. of Science and Technology of China, Anhui (People's Republic of China)
  2. Univ. of Science and Technology of China, Anhui (People's Republic of China); Univ. of Wisconsin-Madison, Madison, WI (United States)
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1474295
Alternate Identifier(s):
OSTI ID: 1377086
Grant/Contract Number:  
FG02-86ER53218; AC02-05CH11231; FC02-08ER54975
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 9; 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

Cheng, Shikui, Zhu, Ping, and Banerjee, Debabrata. Enhanced toroidal flow stabilization of edge localized modes with increased plasma density. United States: N. p., 2017. Web. doi:10.1063/1.4990978.
Cheng, Shikui, Zhu, Ping, & Banerjee, Debabrata. Enhanced toroidal flow stabilization of edge localized modes with increased plasma density. United States. https://doi.org/10.1063/1.4990978
Cheng, Shikui, Zhu, Ping, and Banerjee, Debabrata. Mon . "Enhanced toroidal flow stabilization of edge localized modes with increased plasma density". United States. https://doi.org/10.1063/1.4990978. https://www.osti.gov/servlets/purl/1474295.
@article{osti_1474295,
title = {Enhanced toroidal flow stabilization of edge localized modes with increased plasma density},
author = {Cheng, Shikui and Zhu, Ping and Banerjee, Debabrata},
abstractNote = {Toroidal flow alone is generally thought to have an important influence on tokamak edge pedestal stability, even though theoretical analysis often predicts merely a weak stabilizing effect of toroidal flow on the edge localized modes (ELMs) in experimental parameter regimes. For the first time, we find from two-fluid MHD calculations that such a stabilization, however, can be significantly enhanced by increasing the edge plasma density. Our finding resolves a long-standing mystery whether or how toroidal rotation can indeed have an effective influence on ELMs, and explains why the ELM mitigation and suppression by toroidal rotation are more favorably achieved in higher collisionality regime in recent experiments. Furthermore, the finding suggests a new control scheme on modulating toroidal flow stabilization of ELMs with plasma density, along with a new additional constraint on the optimal level of plasma density for the desired edge plasma conditions},
doi = {10.1063/1.4990978},
journal = {Physics of Plasmas},
number = 9,
volume = 24,
place = {United States},
year = {Mon Aug 28 00:00:00 EDT 2017},
month = {Mon Aug 28 00:00:00 EDT 2017}
}

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Works referenced in this record:

Plasmoids Formation During Simulations of Coaxial Helicity Injection in the National Spherical Torus Experiment
journal, May 2015


Nonlinear magnetohydrodynamics simulation using high-order finite elements
journal, March 2004

  • Sovinec, C. R.; Glasser, A. H.; Gianakon, T. A.
  • Journal of Computational Physics, Vol. 195, Issue 1
  • DOI: 10.1016/j.jcp.2003.10.004

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
  • DOI: 10.1063/1.4751256

Destabilization mechanism of edge localized MHD mode by a toroidal rotation in tokamaks
journal, March 2010


Observations of enhanced core confinement in negative magnetic shear discharges with an L mode edge on DIII-D
journal, October 1996


Physics Design of CFETR: Determination of the Device Engineering Parameters
journal, March 2014

  • Wan, Baonian; Ding, Siye; Qian, Jinping
  • IEEE Transactions on Plasma Science, Vol. 42, Issue 3
  • DOI: 10.1109/TPS.2013.2296939

Edge localized modes (ELMs)
journal, February 1996


Stable equilibria for bootstrap-current-driven low aspect ratio tokamaks
journal, April 1997

  • Miller, R. L.; Lin-Liu, Y. R.; Turnbull, A. D.
  • Physics of Plasmas, Vol. 4, Issue 4
  • DOI: 10.1063/1.872193

Absence of Complete Finite-Larmor-Radius Stabilization in Extended MHD
journal, August 2008


Ballooning instabilities in tokamaks with sheared toroidal flows
journal, March 1991

  • Waelbroeck, F. L.; Chen, L.
  • Physics of Fluids B: Plasma Physics, Vol. 3, Issue 3
  • DOI: 10.1063/1.859858

Impact of the pedestal plasma density on dynamics of edge localized mode crashes and energy loss scaling
journal, December 2014

  • Xu, X. Q.; Ma, J. F.; Li, G. Q.
  • Physics of Plasmas, Vol. 21, Issue 12
  • DOI: 10.1063/1.4905070

Mechanisms of plasma rotation effects on the stability of type-I edge-localized mode in tokamaks
journal, May 2011


Fast Magnetic Reconnection in Laser-Produced Plasma Bubbles
journal, May 2011


Plasma rotation and momentum transport studies at JET
journal, November 2006

  • Vries, P. C. de; Rantamäki, K. M.; Giroud, C.
  • Plasma Physics and Controlled Fusion, Vol. 48, Issue 12
  • DOI: 10.1088/0741-3335/48/12/001

Rotational Stabilization of Magnetically Collimated jets
journal, June 2009


Tail Reconnection Triggering Substorm Onset
journal, August 2008


Ballooning instabilities in tokamaks with sheared toroidal flows
journal, December 1988


Mechanism of Stabilization of Ballooning Modes by Toroidal Rotation Shear in Tokamaks
journal, May 2005


The role of MHD in 3D aspects of massive gas injection
journal, June 2015


Suppression of Plasma Turbulence During Optimized Shear Configurations in JET
journal, February 2000


Coordinated ionospheric observations indicating coupling between preonset flow bursts and waves that lead to substorm onset: SUBSTORM PRECURSOR FLOWS AND WAVES
journal, May 2014

  • Nishimura, Y.; Lyons, L. R.; Nicolls, M. J.
  • Journal of Geophysical Research: Space Physics, Vol. 119, Issue 5
  • DOI: 10.1002/2014JA019773

Localized reconnection in the magnetotail driven by lobe flow channels: Global MHD simulation
journal, February 2016

  • Nishimura, Y.; Lyons, L. R.
  • Journal of Geophysical Research: Space Physics, Vol. 121, Issue 2
  • DOI: 10.1002/2015JA022128

Five-field simulations of peeling-ballooning modes using BOUT++ code
journal, May 2013


Effects of edge collisionality on ELM characteristics in the grassy ELM regime
journal, May 2010


Bursty bulk flows in the inner central plasma sheet
journal, January 1992

  • Angelopoulos, V.; Baumjohann, W.; Kennel, C. F.
  • Journal of Geophysical Research, Vol. 97, Issue A4
  • DOI: 10.1029/91JA02701

Edge pedestal control in quiescent H-mode discharges in DIII-D using co-plus counter-neutral beam injection
journal, July 2009


Inter-machine comparison of intrinsic toroidal rotation in tokamaks
journal, October 2007


Effects of a sheared toroidal rotation on the stability boundary of the MHD modes in the tokamak edge pedestal
journal, May 2009


Focusing of an Explosive Plasma Expansion in a Transverse Magnetic Field
journal, October 2013


Suppression of turbulence and transport by sheared flow
journal, January 2000


Computing nonlinear magnetohydrodynamic edge localized instabilities in fusion plasmas
journal, September 2006


Effect of a deuterium gas puff on the edge plasma in NSTX
journal, July 2014


Stabilizing effects of edge current density on pedestal instabilities
journal, March 2012

  • Zhu, P.; Hegna, C. C.; Sovinec, C. R.
  • Physics of Plasmas, Vol. 19, Issue 3
  • DOI: 10.1063/1.3692089

Turbulent Fluctuations in TFTR Configurations with Reversed Magnetic Shear
journal, October 1996


Influence of toroidal rotation on transport and stability in hybrid scenario plasmas in DIII-D
journal, May 2008


Evaluation of CFETR as a Fusion Nuclear Science Facility using multiple system codes
journal, January 2015


Edge localized linear ideal magnetohydrodynamic instability studies in an extended-magnetohydrodynamic code
journal, March 2010

  • Burke, B. J.; Kruger, S. E.; Hegna, C. C.
  • Physics of Plasmas, Vol. 17, Issue 3
  • DOI: 10.1063/1.3309732

Analysis of a mixed semi-implicit/implicit algorithm for low-frequency two-fluid plasma modeling
journal, August 2010


Plasmoid Formation in Current Sheet with Finite Normal Magnetic Component
journal, June 2013


Magnetorotational Turbulence and Dynamo in a Collisionless Plasma
journal, December 2016


ELM suppression in low edge collisionality H-mode discharges using n = 3 magnetic perturbations
journal, November 2005


Chapter 4: Power and particle control
journal, June 2007


Works referencing / citing this record:

Dominant two-fluid magnetohydrodynamic instabilities in CFETR upgrade phase-I scenario in presence of perfect conducting wall
journal, February 2019

  • Cheng, Shikui; Zhu, Ping; Banerjee, Debabrata
  • Plasma Physics and Controlled Fusion, Vol. 61, Issue 4
  • DOI: 10.1088/1361-6587/ab0090