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

Title: Verification of 5D continuum gyrokinetic code COGENT: Studies of kinetic drift wave instability

Abstract

COGENT (Continuum Gyrokinetic Edge New Technology) is a kinetic plasma simulation code that is being developed by the edge simulation laboratory (ESL) collaboration. The original version of the code has been developed in a 4D phase space (2D configuration space and 2D velocity space) to address kinetic plasma phenomena in a complex magnetic field geometry including the core, magnetic separatrix, and scrape-off layer regions. This paper is focused on extending the original 4D phase space to a 5D phase space (3D2V) to address full kinetic turbulences in a tokamak edge region. Here, we report on the current status of 5D COGENT, which presently operates in a shear-less, simple slab geometry. As a verification study, we use the problems of collision-less drift wave instability (universal instability) including its modification in the presence of collisional effects. The simulation model includes the gyrokinetic equations for ion and electron species coupled to the long-wavelength limit of the gyro-Poisson equation. Collisional effects are represented by the Krook collision model. Linear analytical results for the drift mode growth rate and real frequency are recovered, and the non-linear stage is modelled and analysed as well. In addition, extensive 5D runs have been performed to address the effectsmore » of the drift wave instability on blob/filamentary structures characteristic of a tokamak edge. Finally, a helical-shaped potential perturbation is observed to grow exponentially in time while spinning around the filament axis with electron drift frequency.« less

Authors:
 [1];  [2];  [3];  [4];  [2];  [3];  [2];  [1]
  1. Univ. of California, San Diego, CA (United States). Mechanical and Aerospace Engineering
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Fusion Energy Science Program
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Fusion Energy Science Program. Center for Applied Scientific Computing
  4. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of California, San Diego, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1476212
Alternate Identifier(s):
OSTI ID: 1432721
Report Number(s):
LLNL-JRNL-746119
Journal ID: ISSN 0863-1042; 930713
Grant/Contract Number:  
AC52-07NA27344; FG02-04ER54739; SC0016548
Resource Type:
Accepted Manuscript
Journal Name:
Contributions to Plasma Physics
Additional Journal Information:
Journal Volume: 58; Journal Issue: 6-8; Journal ID: ISSN 0863-1042
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; drift wave; edge; gyrokinetic; kinetic; plasma

Citation Formats

Lee, Wonjae, Dorf, M. A., Dorr, M. R., Cohen, R. H., Rognlien, T. D., Hittinger, J. A. F., Umansky, M. V., and Krasheninnikov, S. I. Verification of 5D continuum gyrokinetic code COGENT: Studies of kinetic drift wave instability. United States: N. p., 2018. Web. doi:10.1002/ctpp.201700161.
Lee, Wonjae, Dorf, M. A., Dorr, M. R., Cohen, R. H., Rognlien, T. D., Hittinger, J. A. F., Umansky, M. V., & Krasheninnikov, S. I. Verification of 5D continuum gyrokinetic code COGENT: Studies of kinetic drift wave instability. United States. doi:10.1002/ctpp.201700161.
Lee, Wonjae, Dorf, M. A., Dorr, M. R., Cohen, R. H., Rognlien, T. D., Hittinger, J. A. F., Umansky, M. V., and Krasheninnikov, S. I. Tue . "Verification of 5D continuum gyrokinetic code COGENT: Studies of kinetic drift wave instability". United States. doi:10.1002/ctpp.201700161. https://www.osti.gov/servlets/purl/1476212.
@article{osti_1476212,
title = {Verification of 5D continuum gyrokinetic code COGENT: Studies of kinetic drift wave instability},
author = {Lee, Wonjae and Dorf, M. A. and Dorr, M. R. and Cohen, R. H. and Rognlien, T. D. and Hittinger, J. A. F. and Umansky, M. V. and Krasheninnikov, S. I.},
abstractNote = {COGENT (Continuum Gyrokinetic Edge New Technology) is a kinetic plasma simulation code that is being developed by the edge simulation laboratory (ESL) collaboration. The original version of the code has been developed in a 4D phase space (2D configuration space and 2D velocity space) to address kinetic plasma phenomena in a complex magnetic field geometry including the core, magnetic separatrix, and scrape-off layer regions. This paper is focused on extending the original 4D phase space to a 5D phase space (3D2V) to address full kinetic turbulences in a tokamak edge region. Here, we report on the current status of 5D COGENT, which presently operates in a shear-less, simple slab geometry. As a verification study, we use the problems of collision-less drift wave instability (universal instability) including its modification in the presence of collisional effects. The simulation model includes the gyrokinetic equations for ion and electron species coupled to the long-wavelength limit of the gyro-Poisson equation. Collisional effects are represented by the Krook collision model. Linear analytical results for the drift mode growth rate and real frequency are recovered, and the non-linear stage is modelled and analysed as well. In addition, extensive 5D runs have been performed to address the effects of the drift wave instability on blob/filamentary structures characteristic of a tokamak edge. Finally, a helical-shaped potential perturbation is observed to grow exponentially in time while spinning around the filament axis with electron drift frequency.},
doi = {10.1002/ctpp.201700161},
journal = {Contributions to Plasma Physics},
number = 6-8,
volume = 58,
place = {United States},
year = {2018},
month = {4}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Figures / Tables:

Figure 1 Figure 1: Implementation of a 5D phase space in COGENT. (a) Electron density distribution in the 3D configuration space. (b) Electron distribution function in the 2D velocity space. The electron density and potential are normalized to n0 = 1020 m-3 and Φ0 = 400V respectively. Normalization number (ref_t) for themore » time variable in Frame (a) is 5.11 x 10-6 s.« less

Save / Share:

Works referenced in this record:

Nonlinear gyrokinetic equations for turbulence in core transport barriers
journal, December 1996


Verification and validation for magnetic fusion
journal, May 2010


Simulation of neoclassical transport with the continuum gyrokinetic code COGENT
journal, January 2013

  • Dorf, M. A.; Cohen, R. H.; Dorr, M.
  • Physics of Plasmas, Vol. 20, Issue 1
  • DOI: 10.1063/1.4776712

Continuum kinetic modeling of the tokamak plasma edge
journal, May 2016

  • Dorf, M. A.; Dorr, M. R.; Hittinger, J. A.
  • Physics of Plasmas, Vol. 23, Issue 5
  • DOI: 10.1063/1.4943106

Electromagnetic drift waves dispersion for arbitrarily collisional plasmas
journal, July 2015

  • Lee, Wonjae; Angus, J. R.; Krasheninnikov, Sergei I.
  • Physics of Plasmas, Vol. 22, Issue 7
  • DOI: 10.1063/1.4927135

Progress with the COGENT Edge Kinetic Code: Collision Operator Options
journal, June 2012

  • Dorf, M. A.; Cohen, R. H.; Compton, J. C.
  • Contributions to Plasma Physics, Vol. 52, Issue 5-6
  • DOI: 10.1002/ctpp.201210042

Drift wave dispersion relation for arbitrarily collisional plasma
journal, May 2012

  • Angus, Justin R.; Krasheninnikov, Sergei I.
  • Physics of Plasmas, Vol. 19, Issue 5
  • DOI: 10.1063/1.4714614

    Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.