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Evidence for electron Landau damping in space plasma turbulence
C H K Chen1, K G Klein2, G G Howes3
1School of Physics and Astronomy, Queen Mary University of London, London, E1 4NS, UK. christopher.chen@qmul.ac.uk.
Nature Communications
|February 16, 2019
Summary
Scientists directly measured energy transfer between electromagnetic fields and electrons in Earth's magnetosheath. Findings suggest electron Landau damping plays a key role in turbulent plasma heating.
Area of Science:
- Plasma physics
- Astrophysical turbulence
- Space plasma
Background:
- Turbulent energy dissipation in weakly collisional plasmas is a significant unresolved problem.
- Understanding particle energization mechanisms in space and astrophysical plasmas is crucial.
Purpose of the Study:
- To directly measure energy transfer between turbulent electromagnetic fields and electrons.
- To investigate the role of electron Landau damping in turbulent plasma heating.
- To validate a field-particle correlation technique for studying plasma energization.
Main Methods:
- Application of a field-particle correlation technique.
- Direct measurement of energy transfer in the Earth's magnetosheath.
- Analysis of energy transfer as a function of electron velocity.
Main Results:
- Observed energy transfer from the parallel electric field to electrons.
- The observed signature is consistent with electron Landau damping.
- The signature is coherent, near resonant velocity, and sensitive to phase randomization.
Conclusions:
- Electron Landau damping is a likely significant mechanism for turbulent plasma heating.
- The field-particle correlation technique is effective for studying particle energization in plasmas.
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