Ion Diffusion and Acceleration in Plasma Turbulence

Abstract

Particle transport, acceleration and energisation are phenomena of major importance for both space and laboratory plasmas. Despite years of study, an accurate theoretical description of these effects is still lacking. Validating models with self-consistent, kinetic simulations represents today a new challenge for the description of weakly-collisional, turbulent plasmas. We perform two-dimensional (2D) hybrid-PIC simulations of steady-state turbulence to study the processes of diffusion and acceleration. The chosen plasma parameters allow to span different systems, going from the solar corona to the solar wind, from the Earth's magnetosheath to confinement devices. To describe the ion diffusion, we adapted the Nonlinear Guiding Center (NLGC) theory to the 2D case. Finally, we investigated the local influence of coherent structures on particle energisation and acceleration: current sheets play an important role if the ions Larmor radii are on the order of the current sheets size. This resonance-like process leads to the violation of the magnetic moment conservation, eventually enhancing the velocity-space diffusion.

arXiv comment24 pages, 16 figures

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Cited by in corpus (14)

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• Ion and Electron Acceleration in Fully Kinetic Plasma Turbulence
• Particle acceleration in strong MHD turbulence
• dHybridR: a Hybrid--Particle-in-Cell Code Including Relativistic Ion Dynamics
• Microphysical Plasma Relations from Special-relativistic Turbulence
• On the Identification of Coherent Structures in Space Plasmas: the Magnetic Helicity-PVI Method
• Parker Solar Probe Observations of Helical Structures as Boundaries for Energetic Particles
• Neutrinos from stochastic acceleration in black hole environments
• Turbulence and particle energization in twisted flux ropes in solar-wind conditions
• Statistical analysis of ions in two-dimensional plasma turbulence
• Effect of the electronic pressure on the energy and magnetic moment of charged test particles in turbulent electromagnetic fields
• Observation of Fermi acceleration with cold atoms
• Simulations Campaign of the Turbulent Diffusion at Tokamaks Edges
• Current sheets, plasmoids and flux ropes in the heliosphere. Part II: Theoretical aspects