Vlasov Simulations of Multi-Ion Plasma Turbulence in the Solar Wind

Perrone, D.; Valentini, F.; Servidio, S.; Dalena, S.; Veltri, P.

doi:10.1088/0004-637x/762/2/99

Cited by 74 publications

(77 citation statements)

References 45 publications

(59 reference statements)

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“…13, which shows the collisional age of protons, 16 demonstrates that the condition T ⊥ /T || ∼ 1 corresponds to a solar wind plasma that is collisionally well-processed ('old') and so remains 'fluid-like', rather than kinetic. The measurements of 'kinetic' turbulence must be qualified by considering the particle pressure anisotropies, and relative drifts between protons and α-particles and protons and electrons (Chen et al 2013b;Perrone et al 2013). close to the ion spectral break) near the thresholds and at higher β || .…”

Section: Ion Scale Instabilities Driven By Solar Wind Expansion and Cmentioning

confidence: 99%

Solar Wind Turbulence and the Role of Ion Instabilities

et al. 2013

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Solar wind is probably the best laboratory to study turbulence in astrophysical plasmas. In addition to the presence of magnetic field, the differences with neutral fluid isotropic turbulence are: (i) weakness of collisional dissipation and (ii) presence of several characteristic space and time scales. In this paper we discuss observational properties of solar wind turbulence in a large range from the MHD to the electron scales. At MHD scales, within the inertial range, turbulence cascade of magnetic fluctuations develops mostly in the plane perpendicular to the mean field, with the Kolmogorov scaling k −5/3 ⊥ for the perpendicular cascade and k −2 for the parallel one. Solar wind turbulence is compressible in nature: density fluctuations at MHD scales have the Kolmogorov spectrum. Velocity fluctuations do not follow magnetic field ones: their spectrum is a power-law with a −3/2 spectral index. Probability distribution functions of different plasma parameters are not Gaussian, indicating presence of intermittency. At the moment there is no global model taking into account all these observed properties of the inertial range. At ion scales, turbulent spectra have a break, compressibility increases and the density fluctuation spectrum has a local flattening. Around ion scales, magnetic spectra are variable and ion instabilities occur as a function of the local plasma parameters. Between ion and electron scales, a small scale turbulent cascade seems to be established. It is characterized by a well defined power-law spectrum in magnetic and density fluctuations with a spectral index close to −2.8. Approaching electron scales, the fluctuations are no more self-similar: an exponential cut-off is usually observed (for time intervals without quasi-parallel whistlers) indicating an onset of dissipation. The small scale inertial range between ion and electron scales and the electron dissipation range can be together described by ∼ k −α ⊥ exp(−k ⊥ d ), with α 8/3 and the dissipation scale d close to the electron Larmor radius d ρ e . The nature of this small scale cascade and a possible dissipation mechanism are still under debate.

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Section: Ion Scale Instabilities Driven By Solar Wind Expansion and Cmentioning

confidence: 99%

Solar Wind Turbulence and the Role of Ion Instabilities

et al. 2013

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“…Here we discuss the numerical results for the kinetic dynamics of alpha particles and protons in decaying turbulence. The plasma dynamics is investigated in a doubly periodic x-y spatial domain perpendicular to a background magnetic field (Perrone et al 2013). In the initial equilibrium the ion species have homogeneous densities and Maxwellian velocity distributions.…”

Section: Vlasov Simulationsmentioning

confidence: 99%

Nonclassical Transport and Particle-Field Coupling: from Laboratory Plasmas to the Solar Wind

et al. 2013

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Understanding transport of thermal and suprathermal particles is a fundamental issue in laboratory, solar-terrestrial, and astrophysical plasmas. For laboratory fusion experiments, confinement of particles and energy is essential for sustaining the plasma long enough to reach burning conditions. For solar wind and magnetospheric plasmas, transport properties determine the spatial and temporal distribution of energetic particles, which can be harmful for spacecraft functioning, as well as the entry of solar wind plasma into the magnetosphere. For astrophysical plasmas, transport properties determine the efficiency of particle acceleration processes and affect observable radiative signatures. In all cases, transport depends on the interaction of thermal and suprathermal particles with the electric and magnetic fluctuations in the plasma. Understanding transport therefore requires us to understand these interactions, which encompass a wide range of scales, from magnetohydrodynamic to kinetic scales, with larger scale structures also having a role. The wealth of transport studies during recent decades has shown the existence of a variety of regimes that differ from the classical quasilinear regime. In this paper we give an overview of nonclassical plasma transport regimes, discussing theoretical approaches to superdiffusive and subdiffusive transport, wave-particle interactions at microscopic kinetic scales, the influence of coherent structures and of avalanching transport, and the results of numerical simulations and experimental data analyses. Applications to laboratory plasmas and space plasmas are discussed.

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“…[19][20][21][22]). Since periodic boundary conditions have been imposed in the spatial numerical domain, we solve Poisson equation through a standard FFT routine.…”

Section: Mathematical Model and Numerical Approachmentioning

confidence: 99%

Eulerian simulations of collisional effects on electrostatic plasma waves

et al. 2013

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The problem of collisions in a plasma is a wide subject with a huge historical literature. In fact, the description of realistic plasmas is a tough problem to attach, both from the theoretical and the numerical point of view, and which requires in general to approximate the original collisional Landau integral by simplified differential operators in reduced dimensionality. In this paper, a Eulerian timesplitting algorithm for the study of the propagation of electrostatic waves in collisional plasmas is presented. Collisions are modeled through one-dimensional operators of the Fokker-Planck type, both in linear and nonlinear form. The accuracy of the numerical code is discussed by comparing the numerical results to the analytical predictions obtained in some limit cases when trying to evaluate the effects of collisions in the phenomenon of wave plasma echo and collisional dissipation of Bernstein-Greene-Kruskal waves. Particular attention is devoted to the study of the nonlinear Dougherty collisional operator, recently used to describe the collisional dissipation of electron plasma waves in a pure electron plasma column [M. W. Anderson and T. M. ONeil, Phys. Plasmas 14, 112110 (2007)]. A receipt to prevent the filamentation problem in Eulerian algorithms is provided by exploiting the property of velocity diffusion operators to smooth out small velocity scales.

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Vlasov Simulations of Multi-Ion Plasma Turbulence in the Solar Wind

Cited by 74 publications

References 45 publications

Solar Wind Turbulence and the Role of Ion Instabilities

Solar Wind Turbulence and the Role of Ion Instabilities

Nonclassical Transport and Particle-Field Coupling: from Laboratory Plasmas to the Solar Wind

Eulerian simulations of collisional effects on electrostatic plasma waves

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