Kinetic heating by Alfvén waves in magnetic shears

Abstract

With first-principles kinetic simulations, we show that a large-scale Alfvén wave (AW) propagating in an inhomogeneous background decays into kinetic Alfvén waves (KAWs), triggering ion and electron energization. We demonstrate that the two species can access unequal amounts of the initial AW energy, experiencing differential heating. During the decay process, the electric field carried by KAWs produces non-Maxwellian features in the particle VDFs, in accordance with space observations. The process we present solely requires the interaction of a large-scale AW with a magnetic shear and may be relevant for several astrophysical and laboratory plasmas.

Accepted in PRL

References in corpus (5)

• Kinetic Simulations of Magnetized Turbulence in Astrophysical Plasmas
• Multiscale nature of the dissipation range in gyrokinetic simulations of Alfvénic turbulence
• Diagnosing collisionless energy transfer using field-particle correlations: gyrokinetic turbulence
• Revisiting a classic: the Parker-Moffatt problem
• Transition to kinetic turbulence at proton scales driven by large-amplitude Kinetic Alfvèn fluctuations