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

Title: Aspects of linear Landau damping in discretized systems

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4792163· OSTI ID:22113423
; ;  [1];  [2]
  1. Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany)
  2. Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Federale de Lausanne (EPFL), Association EURATOM - Confederation Suisse, CH-1015 Lausanne (Switzerland)

Basic linear eigenmode spectra for electrostatic Langmuir waves and drift-kinetic slab ion temperature gradient modes are examined in a series of scenarios. Collisions are modeled via a Lenard-Bernstein collision operator which fundamentally alters the linear spectrum even for infinitesimal collisionality [Ng et al., Phys. Rev. Lett. 83, 1974 (1999)]. A comparison between different discretization schemes reveals that a Hermite representation is superior for accurately resolving the spectra compared to a finite differences scheme using an equidistant velocity grid. Additionally, it is shown analytically that any even power of velocity space hyperdiffusion also produces a Case-Van Kampen spectrum which, in the limit of zero hyperdiffusivity, matches the collisionless Landau solutions.

OSTI ID:
22113423
Journal Information:
Physics of Plasmas, Vol. 20, Issue 2; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
Country of Publication:
United States
Language:
English