Wave dispersion in the hybrid-Vlasov model: Verification of Vlasiator

Journal Article · Fri Nov 15 00:00:00 EST 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4835315· OSTI ID:22218414

Kempf, Yann; Pokhotelov, Dimitry; Koskinen, Hannu E. J. ^[1]; Alfthan, Sebastian von; Palmroth, Minna ^[1]; Vaivads, Andris ^[2]

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1. Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki (Finland)
2. Swedish Institute of Space Physics, Box 537, 751 21 Uppsala (Sweden)

Vlasiator is a new hybrid-Vlasov plasma simulation code aimed at simulating the entire magnetosphere of the Earth. The code treats ions (protons) kinetically through Vlasov's equation in the six-dimensional phase space while electrons are a massless charge-neutralizing fluid [M. Palmroth et al., J. Atmos. Sol.-Terr. Phys. 99, 41 (2013); A. Sandroos et al., Parallel Comput. 39, 306 (2013)]. For first global simulations of the magnetosphere, it is critical to verify and validate the model by established methods. Here, as part of the verification of Vlasiator, we characterize the low-β plasma wave modes described by this model and compare with the solution computed by the Waves in Homogeneous, Anisotropic Multicomponent Plasmas (WHAMP) code [K. Rönnmark, Kiruna Geophysical Institute Reports No. 179, 1982], using dispersion curves and surfaces produced with both programs. The match between the two fundamentally different approaches is excellent in the low-frequency, long wavelength range which is of interest in global magnetospheric simulations. The left-hand and right-hand polarized wave modes as well as the Bernstein modes in the Vlasiator simulations agree well with the WHAMP solutions. Vlasiator allows a direct investigation of the importance of the Hall term by including it in or excluding it from Ohm's law in simulations. This is illustrated showing examples of waves obtained using the ideal Ohm's law and Ohm's law including the Hall term. Our analysis emphasizes the role of the Hall term in Ohm's law in obtaining wave modes departing from ideal magnetohydrodynamics in the hybrid-Vlasov model.

• OSTI ID: 22218414
• Journal Information: Physics of Plasmas, Vol. 20, Issue 11; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANISOTROPY
BERNSTEIN MODE
BOLTZMANN-VLASOV EQUATION
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
ELECTRONS
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MATHEMATICAL SOLUTIONS
OHM LAW
PHASE SPACE
PLASMA
PLASMA SIMULATION
PLASMA WAVES
POLARIZATION
PROTONS
W CODES