Cross-code gyrokinetic verification and benchmark on the linear collisionless dynamics of the geodesic acoustic mode

Research output: Contribution to journalArticle


  • A Biancalani
  • A Bottino
  • C. Ehrlacher
  • Virginie Grandgirard
  • G. Merlo
  • I. Novikau
  • Z. Qiu
  • E. Sonnendrücker
  • X. Garbet
  • T. Görler
  • Susan Leerink

  • F. Palermo
  • D. Zarzoso

Research units

  • Max Planck Institute for Plasma Physics
  • CEA
  • Swiss Federal Institute of Technology Lausanne
  • Zhejiang University
  • CNRS


The linear properties of the geodesic acoustic modes (GAMs) in tokamaks are investigated by means of the comparison of analytical theory and gyrokinetic numerical simulations. The dependence on the value of the safety factor, finite-orbit-width of the ions in relation to the radial mode width, magnetic-flux-surface shaping, and electron/ion mass ratio are considered. Nonuniformities in the plasma profiles (such as density, temperature, and safety factor), electro-magnetic effects, collisions, and the presence of minority species are neglected. Also, only linear simulations are considered, focusing on the local dynamics. We use three different gyrokinetic codes: the Lagrangian (particle-in-cell) code ORB5, the Eulerian code GENE, and semi-Lagrangian code GYSELA. One of the main aims of this paper is to provide a detailed comparison of the numerical results and analytical theory, in the regimes where this is possible. This helps understanding better the behavior of the linear GAM dynamics in these different regimes, the behavior of the codes, which is crucial in the view of a future work where more physics is present, and the regimes of validity of each specific analytical dispersion relation.


Original languageEnglish
Article number062512
Pages (from-to)1-17
JournalPhysics of Plasmas
Issue number6
Publication statusPublished - 1 Jun 2017
MoE publication typeA1 Journal article-refereed

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