Intermittent dissipation and heating in 3D kinetic plasma turbulence

Abstract:

The nature of collisionless dissipation has been hotly
debated in recent years, with alternative ideas posed in
terms of various wave modes, such as kinetic Alfven waves,
whistlers, linear Vlasov instabilities, cyclotron resonance,
and Landau damping. Here we use large scale, fully kinetic
3D simulations of collisionless plasma turbulence which show
the development of turbulence characterized by sheet-like
current density structures spanning a range of scales.
We present evidence that these structures are sites for heating
and dissipation, and that stronger current structures signify
higher dissipation rates. The analyses focus on quantities such
as J.E, electron and proton temperatures, and PVI of the
magnetic field. Evidently, kinetic scale plasma,
like magnetohydrodynamics, becomes intermittent due to
current sheet formation, leading to the expectation
that heating and dissipation in astrophysical and space plasmas
may be highly nonuniform. Comparison with previous
results from 2D kinetic simulations, as well as high frequency
solar wind observational data will also be discussed.