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Title: Toroidally symmetric plasma vortex at tokamak divertor null point

Abstract

Reduced MHD equations are used for studying toroidally symmetric plasma dynamics near the divertor null point. Numerical solution of these equations exhibits a plasma vortex localized at the null point with the time-evolution defined by interplay of the curvature drive, magnetic restoring force, and dissipation. Convective motion is easier to achieve for a second-order null (snowflake) divertor than for a regular x-point configuration, and the size of the convection zone in a snowflake configuration grows with plasma pressure at the null point. In conclusion, the trends in simulations are consistent with tokamak experiments which indicate the presence of enhanced transport at the null point.

Authors:
 [1];  [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1368023
Alternate Identifier(s):
OSTI ID: 1241397
Report Number(s):
LLNL-JRNL-680074
Journal ID: ISSN 1070-664X
Grant/Contract Number:  
AC52-07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 23; Journal Issue: 3; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION; Toroidal plasma confinement; Divertors; Plasma convection; Plasma motion; Fluid equations

Citation Formats

Umansky, M. V., and Ryutov, D. D.. Toroidally symmetric plasma vortex at tokamak divertor null point. United States: N. p., 2016. Web. doi:10.1063/1.4943101.
Umansky, M. V., & Ryutov, D. D.. Toroidally symmetric plasma vortex at tokamak divertor null point. United States. https://doi.org/10.1063/1.4943101
Umansky, M. V., and Ryutov, D. D.. Wed . "Toroidally symmetric plasma vortex at tokamak divertor null point". United States. https://doi.org/10.1063/1.4943101. https://www.osti.gov/servlets/purl/1368023.
@article{osti_1368023,
title = {Toroidally symmetric plasma vortex at tokamak divertor null point},
author = {Umansky, M. V. and Ryutov, D. D.},
abstractNote = {Reduced MHD equations are used for studying toroidally symmetric plasma dynamics near the divertor null point. Numerical solution of these equations exhibits a plasma vortex localized at the null point with the time-evolution defined by interplay of the curvature drive, magnetic restoring force, and dissipation. Convective motion is easier to achieve for a second-order null (snowflake) divertor than for a regular x-point configuration, and the size of the convection zone in a snowflake configuration grows with plasma pressure at the null point. In conclusion, the trends in simulations are consistent with tokamak experiments which indicate the presence of enhanced transport at the null point.},
doi = {10.1063/1.4943101},
journal = {Physics of Plasmas},
number = 3,
volume = 23,
place = {United States},
year = {Wed Mar 09 00:00:00 EST 2016},
month = {Wed Mar 09 00:00:00 EST 2016}
}

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Cited by: 9 works
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Works referenced in this record:

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journal, June 2007


Advanced divertor configurations with large flux expansion
journal, July 2013


Snowflake divertor plasmas on TCV
journal, March 2009


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journal, November 2012


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Ballooning modes localized near the null point of a divertor
journal, April 2014


Power exhaust in the snowflake divertor for L- and H-mode TCV tokamak plasmas
journal, February 2014


Enhanced $\boldsymbol{\vec{{E}}\times \vec{{B}}}$ drift effects in the TCV snowflake divertor
journal, November 2015


Special solutions of the Boussinesq-equations for free convection flows in a vertical gap
journal, July 2003


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Works referencing / citing this record:

Developing physics basis for the snowflake divertor in the DIII-D tokamak
journal, February 2018

  • Soukhanovskii, V. A.; Allen, S. L.; Fenstermacher, M. E.
  • Nuclear Fusion, Vol. 58, Issue 3
  • DOI: 10.1088/1741-4326/aaa6de

The effect of the secondary x-point on the scrape-off layer transport in the TCV snowflake minus divertor
journal, December 2018


Turbulence and flows in the plasma boundary of snowflake magnetic configurations
journal, January 2020