Electron acceleration in the near-Earth magneto-
tail during the substorm period is still an unresolved ques-
tion. In this paper, by tracing electron trajectories in the dy-
namically evolving electromagnetic fields obtained from a
two-dimensional (2D) global hybrid simulation, we investi-
gate electron acceleration in the near-Earth magnetotail dur-
ing dipolarization. In our simulation, electrons with energies
above several keV can gain energy in the plasma sheet due to
the adiabatic acceleration mechanism when these electrons
propagate earthward. In the near-Earth magnetotail (about
9–15 R E from the Earth), these electrons can be accelerated
by betatron acceleration which is due to the compression of
magnetic field associated with dipolarization of magnetotail.
Additionally, in the middle and high latitudes of the near-
Earth magnetotail, the parallel electric field carrying by ki-
netic Alfvén waves can also accelerate electrons when these
electrons bounce between the mirror points. The combina-
tion effects of these three acceleration mechanisms can ac-
celerate electrons from several keV to about one hundred
keV. Our results indicate that both the large-scale structure
and wave-particle interactions need to be taken into account
for electron acceleration in the near-Earth magnetotail.

EB00000003960K

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• Electron acceleration in the near-Earth magnetotail: test particle calculations in electromagnetic fields from two-dimensional hybrid simulations