References of "Physics of Plasmas"
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See detailIn-situ observations of flux ropes formed in association with a pair of spiral nulls in magnetotail plasmas
Guo, Ruilong; Pu, Zuyin; Chen, Li-Jen et al

in Physics of Plasmas (2016), 23(5), 052901

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See detailComparison of formulas for resonant interactions between energetic electrons and oblique whistler-mode waves
Li, Jinxing; Bortnik, Jacob; Xie, Lun et al

in Physics of Plasmas (2015), 22(5), 052902

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See detailOblique propagation of electromagnetic waves in a kappa-Maxwellian plasma
Cattaert, Tom ULiege; Hellberg, M. A.; Mace, R. L.

in Physics of Plasmas (2007), 14(8), 12

Space plasmas are often observed to contain more particles in the high-energy tail than the usual Maxwellian distributions, and are well modeled by kappa distributions. The hybrid kappa-Maxwellian ... [more ▼]

Space plasmas are often observed to contain more particles in the high-energy tail than the usual Maxwellian distributions, and are well modeled by kappa distributions. The hybrid kappa-Maxwellian distribution and associated generalized plasma dispersion function Z(kappa M) were recently introduced to model magnetized space plasmas. The susceptibility tensor for a kappa-Maxwellian plasma component is derived, making use of Z(kappa M). This enables one to make general studies of obliquely propagating electromagnetic waves in a magnetoplasma. The susceptibility and dielectric tensors reduce to the Maxwellian expressions in the limit kappa ->infinity. As an illustration, the formalism is applied to the lower branch of the R mode and its off-parallel variant. For low kappa values, low-wavenumber, low-frequency parallel whistler waves are shown to be stable, unlike the Maxwellian case, which is unstable if the perpendicular temperature exceeds the parallel temperature. A numerical study is made of the effects of the value of kappa, the propagation angle, and the temperature anisotropy ratio on dispersion and damping. The kappa-Maxwellian distribution with very low kappa is found to be unstable in an overdense plasma near the electron-cyclotron frequency even when the parallel and perpendicular temperatures are equal, because of the anisotropy of the contours in velocity space. (C) 2007 American Institute of Physics. [less ▲]

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See detailOn the existence of ion-acoustic double layers in two-electron temperature plasmas
Verheest, F.; Cattaert, Tom ULiege; Hellberg, M. A. et al

in Physics of Plasmas (2006), 13(4), 9

Earlier Sagdeev pseudopotential treatments of ion-acoustic double layers in plasmas with two electron populations were based on a model in which both electron densities were described by isothermal ... [more ▼]

Earlier Sagdeev pseudopotential treatments of ion-acoustic double layers in plasmas with two electron populations were based on a model in which both electron densities were described by isothermal Boltzmann distributions. Using a more recent fluid-dynamical approach, with polytropic equations of state indices gamma(j), one finds analytically that no double layers can be formed for gamma(j)>= 3/2, due to total rarefaction of the cooler electrons or infinite compression of the ions. For gamma(j)< 3/2, rarefactive double layers occur, but, just below 3/2, at unrealistically small cool electron densities or large Mach numbers. As gamma(j) decreases towards 1, these constraints become less restrictive and go over smoothly to those known from Boltzmann studies. Contrary to what appears in the literature, very weak compressive double layers can also be found for Boltzmann electrons, but only for soliton conditions barely above the existence threshold; i.e., marginally super-ion-acoustic. Any slight increase in the critical Mach number destroys the possibility of having positive double layers, and, within the limits of numerical accuracy, no window could be found for gamma(j)not equal 1, where compressive double layers exist.(c) 2006 American Institute of Physics. [less ▲]

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See detailIon- and dust-acoustic solitons in dusty plasmas: Existence conditions for positive and negative potential solutions
Verheest, F.; Cattaert, Tom ULiege; Hellberg, M. A.

in Physics of Plasmas (2005), 12(8), 8

The usual description of dust-modified ion-acoustic and dust-acoustic solitons in plasmas containing negative dust is in terms of Boltzmann distributions for the hotter species. In the dust-modified ion ... [more ▼]

The usual description of dust-modified ion-acoustic and dust-acoustic solitons in plasmas containing negative dust is in terms of Boltzmann distributions for the hotter species. In the dust-modified ion-acoustic regime, besides positive potential solitons, negative structures can also be generated, for electrons with a polytropic index gamma(e)not equal 1, as well as for Boltzmann electrons, subject to conditions that are not too stringent. These general conditions were previously either ignored or given for weakly nonlinear solutions only. In the dust-acoustic domain in plasmas with negatively charged dust, however, only negative potential solitons can occur, even when the lighter species have non-Boltzmann distributions. For Boltzmann electrons only an infinite dust compression limits the soliton amplitudes and corresponding Mach numbers, whereas for gamma(e)not equal 1, the electron density, too, can be a limiting factor for the existence domain of such solitons. (c) 2005 American Institute of Physics. [less ▲]

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See detailLarge amplitude parallel propagating electromagnetic oscillitons
Cattaert, Tom ULiege; Verheest, F.

in Physics of Plasmas (2005), 12(1), 7

Earlier systematic nonlinear treatments of parallel propagating electromagnetic waves have been given within a fluid dynamic approach, in a frame where the nonlinear structures are stationary and various ... [more ▼]

Earlier systematic nonlinear treatments of parallel propagating electromagnetic waves have been given within a fluid dynamic approach, in a frame where the nonlinear structures are stationary and various constraining first integrals can be obtained. This has lead to the concept of oscillitons that has found application in various space plasmas. The present paper differs in three main aspects from the previous studies: first, the invariants are derived in the plasma frame, as customary in the Sagdeev method, thus retaining in Maxwell's equations all possible effects. Second, a single differential equation is obtained for the parallel fluid velocity, in a form reminiscent of the Sagdeev integrals, hence allowing a fully nonlinear discussion of the oscilliton properties, at such amplitudes as the underlying Mach number restrictions allow. Third, the transition to weakly nonlinear whistler oscillitons is done in an analytical rather than a numerical fashion. (C) 2005 American Institute of Physics. [less ▲]

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See detailPotential hill electron-acoustic solitons and double layers in plasmas with two electron species
Cattaert, Tom ULiege; Verheest, F.; Hellberg, M. A.

in Physics of Plasmas (2005), 12(4), 10

In the description of (high-frequency) electron-acoustic solitons in a plasma consisting of positive ions, cool electrons, and hot electrons, the dynamics of the ions plays no essential role and can be ... [more ▼]

In the description of (high-frequency) electron-acoustic solitons in a plasma consisting of positive ions, cool electrons, and hot electrons, the dynamics of the ions plays no essential role and can be eliminated from the treatment, the ions merely providing a constant positive background. It is widely believed that in such a plasma only potential dip solitary waves can be generated. In a potential dip the cooler electrons are compressed and the hotter electrons rarefied, both being driven towards their sonic points, the cooler ones from above, the hotter ones from below. This transonic feature gives rise to the solitary wave. However, it is shown that the restriction to potential dip solitons is due to the neglect of the inertia of the hot electrons, implicitly or explicitly assumed by most-authors. If hot electron inertia is retained, there exists a parameter range where-potential hill solitary waves are formed, with both electron species being driven away from their sonic points This has important consequences for the reinterpretation of several astrophysical phenomena involving two-electron plasmas. (c) 2005 American Institute of Physics. [less ▲]

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See detailOblique propagation of large amplitude electromagnetic solitons in pair plasmas
Verheest, F.; Cattaert, Tom ULiege

in Physics of Plasmas (2005), 12(3), 8

Waves in pair plasmas have a fundamentally different dispersion due to the equal charge-to-mass ratios between negative and positive charges, which mix different time scales. In view of possible ... [more ▼]

Waves in pair plasmas have a fundamentally different dispersion due to the equal charge-to-mass ratios between negative and positive charges, which mix different time scales. In view of possible applications, e. g., to electron-positron and fullerene pair plasmas, stationary nonlinear structures are investigated for oblique or perpendicular propagation with respect to the static magnetic field. A generalized large amplitude extraordinary mode is found, having a linearly polarized electric field that is orthogonal to both the directions of wave propagation and of the static magnetic field. When the Alfvenic Mach number is in a suitably defined range, the pseudoenergy integral admits solutions with a negative wave electric field, in a cone around parallel propagation, and solutions with a positive wave electric field, at all angles of propagation. The exact analytical solution describing these solitary waves has also been obtained. At weakly nonlinear amplitudes, the solutions reduce to familiar solutions of the Korteweg-de Vries or modified Korteweg- de Vries equations. (C) 2005 American Institute of Physics. [less ▲]

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See detailErratum: "Envelope solitons associated with electromagnetic waves in a magnetized pair plasma" [vol 12, pg 012319, 2005]
Cattaert, Tom ULiege; Kourakis, I.; Shukla, P. K.

in Physics of Plasmas (2005), 12(5), 1

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See detailEnvelope solitons associated with electromagnetic waves in a magnetized pair plasma
Cattaert, Tom ULiege; Kourakis, I.; Shukla, P. K.

in Physics of Plasmas (2005), 12(1), 6

The amplitude modulation of magnetic field-aligned circularly polarized electromagnetic (CPEM) waves in a magnetized pair plasma is reexamined. The nonlinear frequency shifts include the effects of the ... [more ▼]

The amplitude modulation of magnetic field-aligned circularly polarized electromagnetic (CPEM) waves in a magnetized pair plasma is reexamined. The nonlinear frequency shifts include the effects of the radiation pressure driven density and compressional magnetic field perturbations as well as relativistic particle mass variations. The dynamics of the modulated CPEM wave packets is governed by a nonlinear Schrodinger equation, which has attractive and repulsive interaction potentials for fast and slow CPEM waves. The modulational stability of a constant amplitude CPEM wave is studied by deriving a nonlinear dispersion from the cubic Schrodinger equation. The fast (slow) CPEM mode is modulationally unstable (stable). Possible stationary amplitude solutions of the modulated fast (slow) CPEM mode can be represented in the form of bright and dark/gray envelope electromagnetic soliton structures. Localized envelope excitations can be associated with the microstructures in pulsar magnetospheres and in laboratory pair magnetoplasmas. (C) 2005 American Institute of Physics. [less ▲]

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See detailLarge amplitude solitary electromagnetic waves in electron-positron plasmas
Verheest, F.; Cattaert, Tom ULiege

in Physics of Plasmas (2004), 11(6), 3078-3082

Waves in electron-positron plasmas have fundamentally different dispersion characteristics due to the equal charge-to-mass ratios between negative and positive charges, which mix different timescales, and ... [more ▼]

Waves in electron-positron plasmas have fundamentally different dispersion characteristics due to the equal charge-to-mass ratios between negative and positive charges, which mix different timescales, and are of interest in understanding aspects of pulsars and active galactic nuclei, where astrophysical electron-positron plasmas occur. Earlier systematic nonlinear treatments of parallel propagating electromagnetic waves via a reductive perturbation analysis had indicated unusual results, namely a vector equivalent of the modified Korteweg-de Vries equation. The latter is nonintegrable except in the case of linear polarization when it becomes equivalent to the scalar (integrable) modified Korteweg-de Vries equation. Here large amplitude purely stationary nonlinear solitary waves are studied in their own reference frame via the McKenzie approach. The behavior of the wave magnetic field can be expressed through an energy integral that involves the Mach number of the structure. Possible solitons are super-Alfvenic and occur symmetrically for positive or negative fields, owing to the obvious symmetry between positive and negative charges with the same mass. The limits on the allowable Mach numbers and soliton amplitudes have also been computed. (C) 2004 American Institute of Physics. [less ▲]

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See detailMagnetosonic modes with a beam of dust or secondary ions
Cramer, N. F.; Verheest, F.; Cattaert, Tom ULiege et al

in Physics of Plasmas (2004), 11(10), 4589-4595

Charged dust particles on near-Keplerian orbits in planetary rings drift relative to the corotating background plasma, and this relative streaming may drive dust-modified magnetosonic waves unstable ... [more ▼]

Charged dust particles on near-Keplerian orbits in planetary rings drift relative to the corotating background plasma, and this relative streaming may drive dust-modified magnetosonic waves unstable. Using a magnetofluid model, this situation is revisited, and it is shown that a correct description can be obtained at frequencies and Doppler shifts that are small compared to the electron gyrofrequency. An excellent agreement is reached between the analytical approximation and the numerical solution of the full or reduced dispersion law. A very low-frequency, small wave number beam instability may occur at supermagnetosonic beam velocities of the dust component, but, based on the existing data, is unlikely to play a role in planetary rings. Instability is also found for submagnetosonic speeds, which might be relevant to Saturn's E ring. (C) 2004 American Institute of Physics. [less ▲]

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See detailElectromagnetic modes in dusty plasmas with charge and mass distributions
Verheest, F.; Cattaert, Tom ULiege

in Physics of Plasmas (2003), 10(4), 956-962

Electromagnetic modes in dusty plasmas are studied for polydisperse dust grains with a distribution in charge and mass. Owing to the different charge and mass weightings of the velocities, there occurs an ... [more ▼]

Electromagnetic modes in dusty plasmas are studied for polydisperse dust grains with a distribution in charge and mass. Owing to the different charge and mass weightings of the velocities, there occurs an infinite chain of equations of motion, coupled through the magnetic part of the Lorentz force. Depending on the frequency and associated convergence regimes, one has to close the chain in ascending or in descending order. Both series together lead to the polydisperse dispersion law that is a generalization of monodisperse or size distributed dust. Power-law distributions typical for heliospheric plasmas are discussed as an application. (C) 2003 American Institute of Physics. [less ▲]

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See detailANOMALOUS PERTURBATIVE TRANSPORT IN TOKAMAKS DUE TO DRIFT-ALVEN-WAVE TURBULENCE
Thoul, Anne ULiege; SIMILON, P. L.; SUDAN, R. N.

in Physics of Plasmas (1994), 1(3), 601-608

The method developed in Thoul, Similon, and Sudan [Phys. Plasmas 1, 579 (1994)] is used to calculate the transport due to drift-Alfven-wave turbulence, in which electromagnetic effects such as the ... [more ▼]

The method developed in Thoul, Similon, and Sudan [Phys. Plasmas 1, 579 (1994)] is used to calculate the transport due to drift-Alfven-wave turbulence, in which electromagnetic effects such as the fluttering of the magnetic field lines are important. Explicit expressions are obtained for all coefficients of the anomalous transport matrix relating particle and heat fluxes to density and temperature gradients in the plasma. Although the magnetic terms leave the transport by trapped electrons unaffected, they are important for the transport by circulating electrons. [less ▲]

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See detailANOMALOUS PERTURBATIVE TRANSPORT IN TOKAMAKS DUE TO DRIFT-WAVE TURBULENCE
Thoul, Anne ULiege; SIMILON, P. L.; SUDAN, R. N.

in Physics of Plasmas (1994), 1(3), 579-600

A new method for calculating the anomalous transport in tokamak plasmas is presented. The renormalized nonlinear plasma response function is derived using the direct-interaction approximation (DIA). A ... [more ▼]

A new method for calculating the anomalous transport in tokamak plasmas is presented. The renormalized nonlinear plasma response function is derived using the direct-interaction approximation (DIA). A complete calculation for the case of electrostatic drift-wave turbulence is presented. Explicit expressions for all coefficients of the anomalous transport matrix relating particle and heat fluxes to density and temperature gradients in the plasma are obtained. The anomalous transport matrix calculated using the DIA does not have the Onsager symmetry. As an example of application, the parameters of the Texas Experimental Tokamak (TEXT) [Nucl. Technol. Fusion 1, 479 (1981)] are used to evaluate all transport coefficients numerically, as well as the spectrum modulation. The relation between the theoretical results and the experimental data is discussed. Although this paper focuses on electron transport for simplicity, the method can also be used to calculate anomalous transport due to ion instabilities, such as the ion-temperature-gradient instability. [less ▲]

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