Current sheet collapse and the onset of reconnection in critically-balanced plasma turbulence.
Abstract
Critically balanced Alfvénic turbulence naturally forms highly anisotropic current sheets. Recently, it has been realised that, under certain physical conditions, these current sheets can undergo magnetic reconnection, disrupting the dramatically changing the nature of the turbulence at the small scales, in both collisional and collisionless plasmas. In the collisionless case, whether or not the current sheets reconnect at scales larger than the characteristic ion kinetic scales or not depends on the plasma beta and the length of the inertial range. We examine the physics of the reconnection process of current sheets that have thicknesses smaller than the ion scales, and show that, in the absence of reconnection onset, sheets can continue to collapse all the way down to electron scales. We then show under what conditions electron-only reconnection onset occurs in these sheets. Finally, we propose that plasma turbulence may be productively thought of as an ensemble of critically-balanced, collapsing current sheets, and thus develop a family of intermittent turbulence models for the reconnecting kinetic-Alfvén-wave turbulence between the ion and electron scales, which could be tested against data from spacecraft in the Solar Wind.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH31A..01M
- Keywords:
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- 7829 Kinetic waves and instabilities;
- SPACE PLASMA PHYSICS;
- 7835 Magnetic reconnection;
- SPACE PLASMA PHYSICS;
- 7836 MHD waves and instabilities;
- SPACE PLASMA PHYSICS;
- 7863 Turbulence;
- SPACE PLASMA PHYSICS