HR: 1330h
AN: SM23B-14    [Abstracts]
TI: Production of Energetic Electrons During Magnetic Reconnection
AU: * Drake, J F
EM: drake@plasma.umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742 United States
AU: Shay, M
EM: shay@glue.umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742 United States
AU: Swisdak, M
AF: Naval Research Laboratory, Plasma Physics Division NRL, Washington DC, 20375 United States
AB: The production of energetic electrons has been documented in observations of solar flares, reconnection in the Earth's magnetosphere and in laboratory experiments yet the understanding of these widespread observations remains poor. In reconnection with a guide field electron acceleration takes place in acceleration cavities, deep depressions in the electron and ion density with finite parallel electric field that extend through the x-line along one of the magnetic separatrices. The structure of these cavities and electron acceleration has been explored in full particle simulations. The simulations reveal distinct high energy tails, extending well above the electron rest energy. These very energetic electrons are found to arise from multiple encounters with acceleration cavities. The simulations provide evidence that reconnection with a guide field is dominated by the formation of many islands and that electron energization results from multiple accelerations. In this picture the surprising amount of energy going into electrons in comparison with ions is first because of the significant length of the acceleration cavities (large numbers of electrons enter the cavities) and because of their high mobility -- they can rapidly interact with many cavities to reach high energy. Ongoing efforts to understand the powerlaw energy distributions of electrons seen in recent Wind satellite observations will be discussed.
DE: 7835 Magnetic reconnection
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly