2017/07/21 by Gregory G. Howes, G. G. Howes, Andrew J. McCubbin +2
Physics and Astronomy · #Classical mechanics #Computational physics #Gyrokinetics #Ionosphere and magnetosphere dynamics #Landau damping #Magnetic confinement fusion research #Mechanics #Nonlinear system #Physics #Plasma #Quantum electrodynamics #Quantum mechanics #Solar and Space Plasma Dynamics #Tokamak #Turbulence #Wave turbulence #astro-ph.SR #physics.plasm-ph #physics.space-ph
paper · pdf · doi:10.1017/s0022377818000053
34 pages, 17 figures, submitted to Journal of Plasma Physics
arxiv created 2017/07/21 · openalex publication_date 2018/01/24 · arxiv updated 2018/03/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Understanding the removal of energy from turbulent fluctuations in a magnetized plasma and the consequent energization of the constituent plasma particles is a major goal of heliophysics and astrophysics. Previous work has shown that nonlinear interactions among counterpropagating Alfvén waves – or Alfvén wave collisions – are the fundamental building block of astrophysical plasma turbulence and naturally generate current sheets in the strongly nonlinear limit. A nonlinear gyrokinetic simulation of a strong Alfvén wave collision is used to examine the damping of the electromagnetic fluctuations and the associated energization of particles that occurs in self-consistently generated current sheets. A simple model explains the flow of energy due to the collisionless damping and the associated particle energization, as well as the subsequent thermalization of the particle energy by collisions. The net particle energization by the parallel electric field is shown to be spatially localized, and the nonlinear evolution is essential in enabling spatial non-uniformity. Using the recently developed field–particle correlation technique, we show that particles resonant with the Alfvén waves in the simulation dominate the energy transfer, demonstrating conclusively that Landau damping plays a key role in the spatially localized damping of the electromagnetic fluctuations and consequent energization of the particles in this strongly nonlinear simulation.