Journal article
Spatially localized particle energization by Landau damping in current sheets produced by strong Alfven wave collisions
Journal of plasma physics, Vol.84(1), 905840105
02/01/2018
DOI: 10.1017/S0022377818000053
Abstract
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 Alfven waves - or Alfven 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 Alfven 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 Alfven 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.
Details
- Title: Subtitle
- Spatially localized particle energization by Landau damping in current sheets produced by strong Alfven wave collisions
- Creators
- Gregory G. Howes - University of IowaAndrew J. McCubbin - Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USAKristopher G. Klein - Univ Michigan, Dept Climate & Space Sci & Engn, Ann Arbor, MI 48109 USA
- Resource Type
- Journal article
- Publication Details
- Journal of plasma physics, Vol.84(1), 905840105
- DOI
- 10.1017/S0022377818000053
- ISSN
- 0022-3778
- eISSN
- 1469-7807
- Publisher
- Cambridge Univ Press
- Number of pages
- 39
- Grant note
- NNX16AM23G / NASA HSR grant University of Iowa Mathematical and Physical Sciences Funding Program AGS-1054061 / NSF; National Science Foundation (NSF) ACI-1053575; PHY090084 / National Science Foundation through NSF XSEDE Award DE-SC0014599 / DOE; United States Department of Energy (DOE)
- Language
- English
- Date published
- 02/01/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984442196102771
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