Electron surfing acceleration due to polarized electric field in reconnection

Masahiro Hoshino

Abstract: The role of non-thermal particle acceleration by reconnection
becomes important in many astroplasma and space plasma phenomena.  We give
one of the updated ideas on the non-thermal particle acceleration in the
course of magnetic reconnection by drawing from particle-in-cell simulation
and satellite observations.  We discuss that high energy electrons are
generated near the X-type region due to a surfing acceleration mechanism.
In a driven reconnection system, the strong polarized electric fields
directing towards the neutral sheet are formed near the X-type neutral
lines in association with the Hall electric current, and the fields play an
important role to interfere with the electrons entering into the neutral
sheet.  During the trapping of electrons by the electrostatic potential
well of the polarized field, the electrons can gain their energies from the
convection/inductive reconnection electric fields.  By this mechanism,
relativistic electrons are quickly generated in and around the X-type
neutral region.