Cluster Observations of Energetic Electron Acceleration Within Earthward Reconnection Jet and Associated Magnetic Flux Rope. Issue 8 (20th August 2021)

• Record Type: Journal Article
• Authors: Vaivads, A.; Khotyaintsev, Yu. V.; Retinò, A.; Fu, H. S.; Kronberg, E. A.; Daly, P. W.
• Is Part Of: Journal of geophysical research. Volume 126:Issue 8(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-08-20
• Subjects: magnetic reconnection -- energetic electrons -- magnetic flux rope; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2021JA029545
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: We study acceleration of energetic electrons in an earthward plasma jet due to magnetic reconnection in the Earth magnetotail for one case observed by Cluster. The case has been selected based on the presence of high fluxes of energetic electrons, Cluster being in the burst mode and Cluster separation being around 1, 000 km that is optimal for studies of ion scale physics. We show that two characteristic acceleration mechanisms are operating during this event. First, significant acceleration is achieved inside the magnetic flux pile‐up of the jet, the acceleration mechanism being consistent with betatron acceleration. Second, strong energetic electron acceleration occurs in magnetic flux rope like structure forming in front of the magnetic flux pile‐up region. Energetic electrons inside the magnetic flux rope are accelerated predominantly in the field‐aligned direction and the acceleration can be due to Fermi acceleration in a contracting flux rope. Key Points: Detailed study of energetic electron acceleration in the braking region of earthward propagating reconnection jet Large electron acceleration in the magnetic flux pile‐up region and in a magnetic flux rope in front of the jet The largest energetic electron fluxes are inside the flux rope, probably due to Fermi acceleration process