The microphysics of magnetic reconnection in the presence of small magnetic
shear
Michael Hesse
Abstract
Magnetic reconnection relies on the presence of a localized region in space,
where the frozen flux constraint is violated and particles are not tied
to the magnetic field any longer. The dimensions of this region depend
on the particle species considered, i.e., particles with larger mass become
unmagnetized on larger scales than particles with smaller mass. This property
renders magnetic reconnection a multiscale problem. Further affecting the
magnetic reconnection process is the magnetic shear across the reconnecting
current sheet. Here less magnetic shear involves a potentially large (guide)
magnetic field component in the reconnection region, which leads to stronger
electron magnetization and accordingly to changes of the magnetic diffusion
process. In order to study collisionless reconnection in this regime, we
will compare models of high shear (anti-parallel) magnetic reconnection
with models with smaller magnetic shear. We will discuss the geometry changes
involved, and the modifications to the reconnection rate and physical scaling
caused by strong guide magnetic fields. We will support our theoretical
estimates with self-consistent particle-in-cell simulations.
Organization: Electrodynamics Branch
NASA Goddard Space Flight Center