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

Title: Verification of long wavelength electromagnetic modes with a gyrokinetic-fluid hybrid model in the XGC code

Abstract

As an alternative option to kinetic electrons, the gyrokinetic total-f particle-in-cell (PIC) code XGC1 has been extended to the MHD/fluid type electromagnetic regime by combining gyrokinetic PIC ions with massless drift-fluid electrons. Here, two representative long wavelength modes, shear Alfven waves and resistive tearing modes, are verified in cylindrical and toroidal magnetic field geometries.

Authors:
ORCiD logo [1];  [2]; ORCiD logo [1]; ORCiD logo [1];  [3];  [3];  [4]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. Intel Corp., Santa Clara, CA (United States)
  3. Univ. of Colorado, Boulder, CO (United States)
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (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) (SC-24)
OSTI Identifier:
1367335
Alternate Identifier(s):
OSTI ID: 1361889
Report Number(s):
PPPL-5394
Journal ID: ISSN 1070-664X; PHPAEN
Grant/Contract Number:
AC02-09CH11466
Resource Type:
Journal Article: 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; finite-elements; simulations; plasma; perturbations; instabilities; algorithm; transport; tokamaks

Citation Formats

Hager, Robert, Lang, Jianying, Chang, C. S., Ku, S., Chen, Y., Parker, S. E., and Adams, M. F. Verification of long wavelength electromagnetic modes with a gyrokinetic-fluid hybrid model in the XGC code. United States: N. p., 2017. Web. doi:10.1063/1.4983320.
Hager, Robert, Lang, Jianying, Chang, C. S., Ku, S., Chen, Y., Parker, S. E., & Adams, M. F. Verification of long wavelength electromagnetic modes with a gyrokinetic-fluid hybrid model in the XGC code. United States. doi:10.1063/1.4983320.
Hager, Robert, Lang, Jianying, Chang, C. S., Ku, S., Chen, Y., Parker, S. E., and Adams, M. F. Wed . "Verification of long wavelength electromagnetic modes with a gyrokinetic-fluid hybrid model in the XGC code". United States. doi:10.1063/1.4983320.
@article{osti_1367335,
title = {Verification of long wavelength electromagnetic modes with a gyrokinetic-fluid hybrid model in the XGC code},
author = {Hager, Robert and Lang, Jianying and Chang, C. S. and Ku, S. and Chen, Y. and Parker, S. E. and Adams, M. F.},
abstractNote = {As an alternative option to kinetic electrons, the gyrokinetic total-f particle-in-cell (PIC) code XGC1 has been extended to the MHD/fluid type electromagnetic regime by combining gyrokinetic PIC ions with massless drift-fluid electrons. Here, two representative long wavelength modes, shear Alfven waves and resistive tearing modes, are verified in cylindrical and toroidal magnetic field geometries.},
doi = {10.1063/1.4983320},
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}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on May 24, 2018
Publisher's Version of Record

Save / Share:
  • The fluid-kinetic hybrid electron model is verified in global gyrokinetic particle simulation of linear electromagnetic drift-Alfvenic instabilities in tokamak. In particular, we have recovered the {beta}-stabilization of the ion temperature gradient mode, transition to collisionless trapped electron mode, and the onset of kinetic ballooning mode as {beta}{sub e} (ratio of electron kinetic pressure to magnetic pressure) increases.
  • A linear gyrokinetic system for arbitrary wavelength electromagnetic modes is developed. A wide range of modes in inhomogeneous plasmas, such as the internal kink modes, the toroidal Alfv{acute e}n eigenmode (TAE) modes, and the drift modes, can be recovered from this system. The inclusion of most of the interesting physical factors into a single framework enables one to look at many familiar modes simultaneously, and thus to study the modifications of and the interactions between them in a systematic way. Especially, it is possible to investigate self-consistently the kinetic magnetohydrodynamics (MHD) phenomena entirely from the kinetic side. Phase space Lagrangianmore » Lie perturbation methods and a newly developed computer algebra package for vector analysis in general coordinate system are utilized in the analytical derivation. In tokamak geometries, a two-dimensional finite element code has been developed and tested. In this paper, the basic theoretical formalism and some of the preliminary results are presented. {copyright} {ital 1998 American Institute of Physics.}« less
  • A kinetic electron closure scheme is presented for the fluid electron model that has been implemented in the GEM code [J. Lang, Y. Chen, S. E. Parker, and G.-Y. Fu, Phys. Plasmas 16, 102101 (2009)]. The most important element of the closure scheme is a complete Ohm's law for the parallel electric field E{sub ||}, derived by combining the quasineutrality condition, the Ampere's equation and the v{sub ||} moment of the gyrokinetic equations. A discretization method for the closure scheme is presented and studied in detail for a three-dimensional shearless slab plasma. It is found that for long wavelength shearmore » Alfven waves the kinetic closure scheme is both more accurate and more robust than the previous GEM algorithm [Y. Chen and S. E. Parker, J. Comput. Phys. 189, 463 (2003)], whereas for the ion-gradient-driven instability the previous algorithm is more efficient. The fluid electron model with kinetic electron closure is useful for studying energetic particles driven modes with electron kinetic damping effects.« less
  • The kinetic ballooning mode (KBM) has been shown in previous work to be unstable within the magnetohydrodynamic (MHD) region (in s-{alpha} space) of second stability [Hirose et al., Phys. Rev. Lett. 72, 3993 (2004)]. In this work we verify this result using the gyrokinetic code GS2 [Kotschenreuther et al., Comput. Phys. Commun. 88, 128 (1996)] treating both ions and electrons as kinetic species and retaining the magnetosonic perturbation B{sub parallel}. Growth rates calculated using GS2 differ significantly from the previous differential/shooting code analysis. Calculations without B{sub parallel} find the stability region is preserved, while the addition of B{sub parallel} causesmore » the mode to be more unstable than previously calculated within the region of MHD second stability. The inclusion of parallel ion current and B{sub parallel} into the shooting code does not account for the GS2 results. The evidence presented in this paper leads us to the conclusion that the adiabatic electron approximation employed in previous studies is found to be unsuitable for this type of instability. Based on the findings of this work, the KBM becomes an interesting instability in the context of internal transport barriers, where {alpha} is often large and magnetic shear is small (positive or negative)« less