skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Pressure balance in a lower collisionality, attached tokamak scrape-off layer

Abstract

Previously the gyrokinetic neoclassical code XGCa found that the pressure balance (or momentum balance) in the diverted scrape-off layer (SOL) does not follow that from the fluid description based on the Chew–Goldberger–Low (CGL) theory. In this paper a gyrocenter parallel momentum moment equation is derived for pressure balance (or momentum balance) in a tokamak SOL, for use in interpreting this difference. The new gyrocenter-fluid pressure balance equation allows identifying from the XGCa code results which physical processes dominate the setting of pressure variation in the scrape-off layer. This pressure balance equation is applied to the simulation of a DIII-D H-mode discharge, with a lower ion collisionality in the SOL, and the Coulomb and atomic collisions are not strong enough to yield a detached divertor plasma. It is found that the total pressure balance is much better matched using the gyrocenter parallel momentum moment equation. Electrons are shown to be dominantly adiabatic, while ions have multiple contributions to pressure balance, including terms originating from particle drifts. Furthermore, these results show that in strong gradient, low collisionality regions of the SOL, the typical fluid reductions miss important effects captured in the gyrokinetic model.

Authors:
ORCiD logo [1];  [1];  [1];  [1];  [1]; ORCiD logo [1];  [1]
+ Show Author Affiliations
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
OSTI Identifier:
1558759
Grant/Contract Number:  
AC02-05CH11231; AC02-09CH11466; FC02-04ER54698
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 59; Journal Issue: 9; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; scrape-off layer; tokamak; gyrokinetic; simulation

Citation Formats

Churchill, R. M., Chang, C. S., Ku, S., Hager, R., Maingi, R., Stotler, D. P., and Qin, H. Pressure balance in a lower collisionality, attached tokamak scrape-off layer. United States: N. p., 2019. Web. doi:10.1088/1741-4326/ab2af9.
Copy to clipboard
Churchill, R. M., Chang, C. S., Ku, S., Hager, R., Maingi, R., Stotler, D. P., & Qin, H. Pressure balance in a lower collisionality, attached tokamak scrape-off layer. United States. doi:https://doi.org/10.1088/1741-4326/ab2af9
Copy to clipboard
Churchill, R. M., Chang, C. S., Ku, S., Hager, R., Maingi, R., Stotler, D. P., and Qin, H. Fri . "Pressure balance in a lower collisionality, attached tokamak scrape-off layer". United States. doi:https://doi.org/10.1088/1741-4326/ab2af9. https://www.osti.gov/servlets/purl/1558759.
Copy to clipboard
@article{osti_1558759,
title = {Pressure balance in a lower collisionality, attached tokamak scrape-off layer},
author = {Churchill, R. M. and Chang, C. S. and Ku, S. and Hager, R. and Maingi, R. and Stotler, D. P. and Qin, H.},
abstractNote = {Previously the gyrokinetic neoclassical code XGCa found that the pressure balance (or momentum balance) in the diverted scrape-off layer (SOL) does not follow that from the fluid description based on the Chew–Goldberger–Low (CGL) theory. In this paper a gyrocenter parallel momentum moment equation is derived for pressure balance (or momentum balance) in a tokamak SOL, for use in interpreting this difference. The new gyrocenter-fluid pressure balance equation allows identifying from the XGCa code results which physical processes dominate the setting of pressure variation in the scrape-off layer. This pressure balance equation is applied to the simulation of a DIII-D H-mode discharge, with a lower ion collisionality in the SOL, and the Coulomb and atomic collisions are not strong enough to yield a detached divertor plasma. It is found that the total pressure balance is much better matched using the gyrocenter parallel momentum moment equation. Electrons are shown to be dominantly adiabatic, while ions have multiple contributions to pressure balance, including terms originating from particle drifts. Furthermore, these results show that in strong gradient, low collisionality regions of the SOL, the typical fluid reductions miss important effects captured in the gyrokinetic model.},
doi = {10.1088/1741-4326/ab2af9},
journal = {Nuclear Fusion},
number = 9,
volume = 59,
place = {United States},
year = {2019},
month = {7}
}
Copy to clipboard
Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI:  https://doi.org/10.1088/1741-4326/ab2af9
Copyright Statement
Other availability
Search WorldCat Search WorldCat to find libraries that may hold this journal
Save / Share:
Export Metadata
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:

A new hybrid-Lagrangian numerical scheme for gyrokinetic simulation of tokamak edge plasma
journal, June 2016

Total fluid pressure imbalance in the scrape-off layer of tokamak plasmas
journal, March 2017

A fast low-to-high confinement mode bifurcation dynamics in the boundary-plasma gyrokinetic code XGC1
journal, May 2018

  • Ku, S.; Chang, C. S.; Hager, R.
  • Physics of Plasmas, Vol. 25, Issue 5
  • DOI: 10.1063/1.5020792

Neoclassical viscosity of a tokamak plasma with large mass flow
journal, December 1993

  • Chang, C. S.
  • Physics of Fluids B: Plasma Physics, Vol. 5, Issue 12
  • DOI: 10.1063/1.860553

Variational principles of guiding centre motion
journal, February 1983

Nonlinear gyrokinetic equations for tokamak microturbulence
journal, September 1988

Gyrokinetic particle simulation model
journal, September 1987

Fluid moment models for Landau damping with application to the ion-temperature-gradient instability
journal, June 1990

Basic physical processes and reduced models for plasma detachment
journal, March 2018

Overview of the DIII-D Fusion Science Program
journal, October 2005

  • Luxon, J. L.; Simonen, T. C.; Stambaugh, R. D.
  • Fusion Science and Technology, Vol. 48, Issue 2
  • DOI: 10.13182/FST05-A1041

Nonlinear gyrofluid description of turbulent magnetized plasmas
journal, May 1992

  • Brizard, Alain
  • Physics of Fluids B: Plasma Physics, Vol. 4, Issue 5
  • DOI: 10.1063/1.860129

Gyrofluid turbulence models with kinetic effects
journal, March 1993

  • Dorland, W.; Hammett, G. W.
  • Physics of Fluids B: Plasma Physics, Vol. 5, Issue 3
  • DOI: 10.1063/1.860934

A Suitable Boundary Condition for Bounded Plasma Simulation without Sheath Resolution
journal, January 1993

  • Parker, S. E.; Procassini, R. J.; Birdsall, C. K.
  • Journal of Computational Physics, Vol. 104, Issue 1
  • DOI: 10.1006/jcph.1993.1005

Gyrofluid simulations of turbulence suppression in reversed-shear experiments on the Tokamak Fusion Test Reactor
journal, May 1997

  • Beer, M. A.; Hammett, G. W.; Rewoldt, G.
  • Physics of Plasmas, Vol. 4, Issue 5
  • DOI: 10.1063/1.872279

Viscosity in a magnetized plasma: Physical interpretation
journal, August 1985

  • Hollweg, Joseph V.
  • Journal of Geophysical Research: Space Physics, Vol. 90, Issue A8
  • DOI: 10.1029/JA090iA08p07620

Two-point analysis of the numerical modelling of detached divertor plasmas
journal, October 2009

Kinetic simulations of scrape-off layer physics in the DIII-D tokamak
journal, August 2017

Foundations of nonlinear gyrokinetic theory
journal, April 2007

    [ × clear filter / sort ]

    Similar Records in DOE PAGES and OSTI.GOV collections: