Observations of wave-particle interactions in the flux pile-up region of asymmetric reconnection.
Résumé
Recent observations have shown electron energization to >100keV with simultaneous whistler wave activity in the vicinity of the dayside reconnection site. We investigate one possible mechanism for producing these energetic particles. The Electron Drift Instrument on MMS is capable of detecting wave-particle interactions up to 512 Hz. Whistler waves in this frequency range are generated in the flux pile-up region of reconnection. We find that the growing magnetic field gradient due to flux pile-up is responsible for electron bounce motion and betatron acceleration that increase the temperature anisotropy required for whistler wave growth. The whistler waves then energize and scatter electrons, freeing them to be further accelerated by other processes.