Current sheet particle acceleration: Theory and observations for the geomagnetic tail

Simple models exist which allow particle orbits in current sheets to be calculated analytically. An electric field consistent with reconnection topologies can be added. However, for the case of a constant normal magnetic field, the electric field can be transformed away. In this DeHoffman-Teller frame, particle energy is conserved and for many classes of particles, pitch angle (before and after interaction with the sheet) is approximately conserved. Comparison of such models, with temporal and/or spatial variations, is made with observations of particle distribution functions in the tail and with observed ion beams in the plasma sheet boundary layer.