Journal article
Collisionless energy transfer in kinetic turbulence: field–particle correlations in Fourier space
Journal of plasma physics, Vol.85(4), 905850406
08/01/2019
DOI: 10.1017/S0022377819000515
Abstract
Turbulence is commonly observed in nearly collisionless heliospheric plasmas, including the solar wind and corona and the Earth’s magnetosphere. Understanding the collisionless mechanisms responsible for the energy transfer from the turbulent fluctuations to the particles is a frontier in kinetic turbulence research. Collisionless energy transfer from the turbulence to the particles can take place reversibly, resulting in non-thermal energy in the particle velocity distribution functions (VDFs) before eventual collisional thermalization is realized. Exploiting the information contained in the fluctuations in the VDFs is valuable. Here we apply a recently developed method based on VDFs, the field–particle correlation technique, to a β=1, solar-wind-like, low-frequency Alfvénic turbulence simulation with well-resolved phase space to identify the field–particle energy transfer in velocity space. The field–particle correlations reveal that the energy transfer, mediated by the parallel electric field, results in significant structuring of the VDF in the direction parallel to the magnetic field. Fourier modes representing the length scales between the ion and electron gyroradii show that energy transfer is resonant in nature, localized in velocity space to the Landau resonances for each Fourier mode. The energy transfer closely follows the Landau resonant velocities with varying perpendicular wavenumber k⊥ and plasma β . This resonant signature, consistent with Landau damping, is observed in all diagnosed Fourier modes that cover the dissipation range of the simulation.
Details
- Title: Subtitle
- Collisionless energy transfer in kinetic turbulence: field–particle correlations in Fourier space
- Creators
- Tak Chu Li - Dartmouth CollegeGregory G. Howes - Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USAKristopher G. Klein - University of ArizonaYi-Hsin Liu - Dartmouth CollegeJason M. TenBarge - Princeton University
- Resource Type
- Journal article
- Publication Details
- Journal of plasma physics, Vol.85(4), 905850406
- Publisher
- Cambridge University Press
- DOI
- 10.1017/S0022377819000515
- ISSN
- 0022-3778
- eISSN
- 1469-7807
- Number of pages
- 31
- Language
- English
- Date published
- 08/01/2019
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984442201702771
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