Explosive Particle Dispersion in Plasma Turbulence.
Particle dynamics are investigated in plasma turbulence, using self-consistent kinetic simulations, in two dimensions. In the steady state, the trajectories of single protons and proton pairs are studied, at different values of plasma β (ratio between kinetic and magnetic pressure). For single-particle displacements, results are consistent with fluids and magnetic field line dynamics, where particles undergo normal diffusion for very long times, with higher β's being more diffusive. In an intermediate time range, with separations lying in the inertial range, particles experience an explosive dispersion in time, consistent with the Richardson prediction. These results, obtained for the first time with a self-consistent kinetic model, are relevant for astrophysical and laboratory plasmas, where turbulence is crucial for heating, mixing, and acceleration processes.
Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy.
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Servidio
School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
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Haynes
Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA.
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Matthaeus
School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
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Burgess
Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy.
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Carbone
Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza, Italy.
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Veltri