Particle Acceleration from Strong Turbulence Driven by Magnetic Reconnection
Abstract
We present observations from the Magnetospheric Multiscale (MMS) satellites that detail non-thermal particle acceleration from strong turbulence in the Earth's magnetotail. The strong turbulence occurs in an extended region (on order of 10 RE) in which magnetic reconnection enables unusually rapid magnetic field annihilation. Turbulent cascade rates exceed 1010 J kg-1s-1 that suggests heating rates of ~5 keV/s per particle pair. The observations suggest that the conversion of electromagnetic energy into particle energy transpires via unusually large-amplitude intermittent (uncorrelated) electric fields that promote second order heating. Strong magnetic field fluctuations (δ|B|/|B| ~ 1) result in regions of depleted magnetic field (magnetic holes) that can temporarily trap ions and electrons. The trapped particles can experience heating from the intermittent electric fields for much longer periods, which results in a non-thermal tail in the electron and ion distributions extending up to several hundreds of keV. Interestingly, magnetic reconnection enables the strong turbulence, which in turn, generates the prime ingredients for the non-thermal particle acceleration, intermittent electric fields and magnetic holes. This acceleration process is applicable to plasmas in astrophysical settings in which regions of strong turbulence can be generated, such as supernova shells. These results suggest that the role of turbulence in particle acceleration should be examined in more detail.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSM32A..09E
- Keywords:
-
- 7835 Magnetic reconnection;
- SPACE PLASMA PHYSICS;
- 7845 Particle acceleration;
- SPACE PLASMA PHYSICS;
- 7863 Turbulence;
- SPACE PLASMA PHYSICS;
- 7867 Wave/particle interactions;
- SPACE PLASMA PHYSICS