Energetic electron acceleration by magnetic
reconnection with surrounding structure

Imada S., M. Hoshino and T. Mukai

By using the Geotail spacecraft data, we study plasma heating and
acceleration around the magnetic reconnection region. We carry out the
superposed analysis of the thermal temperature and energetic electron flux
(> 38keV) as a function of distance from the X-/O-type neutral line, for
the near-Earth, the plasmoid and the distant magnetotail.
What we found are as follows:
(1) Near-Earth
Thermal electrons are effectively heated near the plasma sheet boundary
layer rather than the central plasma sheet, and the highest intensity of
energetic electrons flux can be found at the outflow region away from the
X-type neutral region. The intensity of energetic electrons flux is much
higher in the earth ward flow region than in the tail ward flow region.
(2) Distant tail
There is no clear difference between the earth ward side and the tail ward
side.
(3) Plasmoid
The energetic electrons flux intensity are much higher in outer region of
plasmoid where the magnetic field lines are piling up.
>From these analyses, we argue the acceleration of energetic electrons
produced by not only X-point but the entire magnetic reconnection region
concerning the difference of these three structures.