Electrostatic Landau pole for {kappa}-velocity distributions

Journal Article · Sat Sep 15 04:00:00 EDT 2007 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2776897· OSTI ID:21069823

Valentini, Francesco; D'Agosta, Roberto ^[1]

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1. Dipartimento di Fisica and CNISM, Universita della Calabria, 87036 Rende (Italy)

In this paper, the analytical solution of the linear electrostatic Vlasov dispersion relation is obtained for non-Maxwellian equilibrium distributions of particle velocities ({kappa} distributions). The unphysical singularities for certain values of the parameter {kappa}, recovered by several authors in solving the Landau integral, are discussed in detail, and a way to cancel these singularities and get the correct solution for Langmuir waves is proposed. The solution of the electrostatic dispersion relation presented in this paper provides a theoretical prediction for the oscillation frequency and the damping rate of Langmuir waves, for real values of {kappa}>1/2 and in particular in the range 1/2<{kappa}{<=}3/2, where previous analytical solutions fail. Velocity distributions with small values of {kappa} have been frequently observed in solar wind plasmas; therefore, the results presented in this paper are relevant in the interpretation of the solar wind experimental data. Eulerian Vlasov numerical simulations have been performed to substantiate the analytical results; the numerical results are in very good agreement with the theoretical predictions.

• OSTI ID: 21069823
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 9 Vol. 14; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANALYTICAL SOLUTION
BOLTZMANN-VLASOV EQUATION
COMPUTERIZED SIMULATION
DAMPING
DISPERSION RELATIONS
DISTRIBUTION
EQUILIBRIUM
PLASMA
PLASMA SIMULATION
PLASMA WAVES
SINGULARITY
SOLAR WIND
VELOCITY