A new tool for analyzing microinstabilities in space plasmas modeled by a generalized Lorentzian (Kappa) distribution

1992 ◽  
Vol 97 (A11) ◽  
pp. 16827 ◽  
Author(s):  
Danny Summers ◽  
Richard M. Thorne
Keyword(s):  
Space Plasmas ◽  
Kappa Distribution

scholarly journals Derivation of the entropic formula for the statistical mechanics of space plasmas

2018 ◽  
Vol 25 (1) ◽  
pp. 77-88 ◽  
Author(s):  
George Livadiotis
Keyword(s):  
Statistical Mechanics ◽  
Canonical Ensemble ◽  
Space Plasmas ◽  
Kappa Distribution ◽  
Physical Origin ◽  
Nonextensive Statistical Mechanics

Abstract. Kappa distributions describe velocities and energies of plasma populations in space plasmas. The statistical origin of these distributions is associated with the framework of nonextensive statistical mechanics. Indeed, the kappa distribution is derived by maximizing the q entropy of Tsallis, under the constraints of the canonical ensemble. However, the question remains as to what the physical origin of this entropic formulation is. This paper shows that the q entropy can be derived by adapting the additivity of energy and entropy.

A dielectric tensor for a uniform magnetoplasma with a generalized Lorentzian distribution

1996 ◽  
Vol 55 (3) ◽  
pp. 415-429 ◽  
Author(s):  
R. L. Mace
Keyword(s):  
Magnetic Field ◽  
Wave Propagation ◽  
Magnetized Plasma ◽  
Space Plasmas ◽  
Dielectric Tensor ◽  
Kappa Distribution ◽  
Numerical Studies ◽  
Starting Point ◽  
Limiting Case ◽  
The Magnetic Field

It is demonstrated that the dielectric tensor for a non-relativistic magnetized plasma whose particle velocity distributions can be modelled by isotropic kappa, or generalized Lorentzian, distributions admits an expression similar to that obtained by Trubnikov for a relativistic plasma. The kappa distribution is a useful distribution for modelling space plasmas containing significant numbers of superthermal particles, i.e. those that have energies in excess of the thermal energy. The dielectric tensor is valid for arbitrary wavevectors, and is shown to reproduce the known limiting case of wave propagation parallel to the magnetic field. Even in this limiting case, the results obtained represent a generalization of previous results to arbitrary real values of the index K, the parameter that shapes the superthermal tail on the distribution. The expression for the dielectric tensor might be useful as a starting point for numerical studies of waves and instabilities in plasmas containing superthermal particles.

scholarly journals Derivation of the entropic formula for the statistical mechanics of space plasmas

2017 ◽  
Author(s):  
George Livadiotis
Keyword(s):  
Statistical Mechanics ◽  
Canonical Ensemble ◽  
Space Plasmas ◽  
Kappa Distribution ◽  
Physical Origin

Abstract. Kappa distributions describe velocities and energies of plasma populations in space plasmas. The statistical origin of these distributions is the non-extensive statistical mechanics. Indeed, the kappa distribution is derived by maximizing the q-entropy of Tsallis under the constraints of canonical ensemble. However, there remains the question what is the physical origin of this entropic formulation. This paper shows that the q-entropy can be derived by adapting the additivity of energy and entropy.

Debye length in a kappa-distribution plasma

1996 ◽  
Vol 56 (1) ◽  
pp. 87-93 ◽  
Author(s):  
D. A. Bryant
Keyword(s):  
Velocity Distribution ◽  
Power Law ◽  
Debye Length ◽  
Space Plasmas ◽  
Kappa Distribution ◽  
Number Density ◽  
Electrons And Ions ◽  
Modified Power Law

The Debye length, the characteristic shielding distance in a plasma, is, when the electrons and ions have Maxwellian velocity distributions, determined by the ratio of the temperatures of these components, to the electron (or ion) number density. Plasmas encountered in space, however, commonly exhibit non-Maxwellian velocity distributions, where the evaluation of an appropriate ‘temperature’ from an observed velocity distribution is no longer a recognized procedure. This paper evaluates the shielding distance for a plasma having a modified power-law, or kappa, family of distribuitons characteristic of some space plasmas.

INVARIANT KAPPA DISTRIBUTION IN SPACE PLASMAS OUT OF EQUILIBRIUM

2011 ◽  
Vol 741 (2) ◽  
pp. 88 ◽  
Author(s):  
G. Livadiotis ◽  
D. J. McComas
Keyword(s):  
Space Plasmas ◽  
Kappa Distribution

scholarly journals Dispersive MHD waves and alfvenons in charge non-neutral plasmas

2008 ◽  
Vol 15 (4) ◽  
pp. 681-693 ◽  
Author(s):  
K. Stasiewicz ◽  
J. Ekeberg
Keyword(s):  
Soliton Solutions ◽  
Theoretical Models ◽  
Mhd Waves ◽  
Space Plasmas ◽  
Charge Effects ◽  
Novel Technique ◽  
Solitary Structures ◽  
Spatial Dimensions ◽  
Electric Potentials ◽  
Linear And Nonlinear

Abstract. Dispersive properties of linear and nonlinear MHD waves, including shear, kinetic, electron inertial Alfvén, and slow and fast magnetosonic waves are analyzed using both analytical expansions and a novel technique of dispersion diagrams. The analysis is extended to explicitly include space charge effects in non-neutral plasmas. Nonlinear soliton solutions, here called alfvenons, are found to represent either convergent or divergent electric field structures with electric potentials and spatial dimensions similar to those observed by satellites in auroral regions. Similar solitary structures are postulated to be created in the solar corona, where fast alfvenons can provide acceleration of electrons to hundreds of keV during flares. Slow alfvenons driven by chromospheric convection produce positive potentials that can account for the acceleration of solar wind ions to 300–800 km/s. New results are discussed in the context of observations and other theoretical models for nonlinear Alfvén waves in space plasmas.

scholarly journals General dispersion properties of magnetized plasmas with drifting bi-Kappa distributions. DIS-K: Dispersion Solver for Kappa Plasmas

2021 ◽  
Vol 87 (3) ◽  
Author(s):  
R.A. López ◽  
S.M. Shaaban ◽  
M. Lazar
Keyword(s):  
Dominant Role ◽  
High Energy ◽  
Distribution Functions ◽  
Magnetized Plasma ◽  
Unstable Wave ◽  
Space Plasmas ◽  
Good Representation ◽  
Particle Interactions ◽  
Particle Collisions ◽  
Dispersion Tensor

Space plasmas are known to be out of (local) thermodynamic equilibrium, as observations show direct or indirect evidences of non-thermal velocity distributions of plasma particles. Prominent are the anisotropies relative to the magnetic field, anisotropic temperatures, field-aligned beams or drifting populations, but also, the suprathermal populations enhancing the high-energy tails of the observed distributions. Drifting bi-Kappa distribution functions can provide a good representation of these features and enable for a kinetic fundamental description of the dispersion and stability of these collision-poor plasmas, where particle–particle collisions are rare but wave–particle interactions appear to play a dominant role in the dynamics. In the present paper we derive the full set of components of the dispersion tensor for magnetized plasma populations modelled by drifting bi-Kappa distributions. A new solver called DIS-K (DIspersion Solver for Kappa plasmas) is proposed to solve numerically the dispersion relations of high complexity. The solver is validated by comparing with the damped and unstable wave solutions obtained with other codes, operating in the limits of drifting Maxwellian and non-drifting Kappa models. These new theoretical tools enable more realistic characterizations, both analytical and numerical, of wave fluctuations and instabilities in complex kinetic configurations measured in-situ in space plasmas.

scholarly journals Development of a high-time/spatial resolution self-impedance probe for measurements in laboratory and space plasmas

2021 ◽  
Vol 92 (1) ◽  
pp. 015118
Author(s):  
Ami M. DuBois ◽  
Erik M. Tejero ◽  
George R. Gatling ◽  
William E. Amatucci
Keyword(s):  
Spatial Resolution ◽  
High Time ◽  
Space Plasmas ◽  
Impedance Probe
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