HR: 08:20h
AN: SH41C-02    [Abstracts]
TI: On the filamentary structure of energetic electrons during flares
AU: * Drake, J
EM: drake@umd.edu
AF: UC Berkeley, 7 Gauss Way, Berkeley, CA 74720-7450, United States
AU: Swisdak, M
EM: swisdak@umd.edu
AF: U Maryland, IREAP University of Maryland, College Park, MD 20770, United States
AU: Shay, M
EM: shay@udel.edu
AF: U Delaware, Department of Physics and Astronomy 217 Sharp Lab, Newark, DE 19716, United States
AB: Simulations and analytic arguments are presented that demonstrate that magnetic reconnection in the tenuous high temperature corona does not occur as a single large-scale x-line. Rather the narrow current layers that form at x-lines form secondary magnetic islands at small spatial scales. An electron acceleration model based on the interaction of particles with many contracting islands has been developed. A consequence of particle acceleration in any multi-island system is that energetic particles are released in narrow streams with characteristic widths of the order of the electron skin depth. This is because electrons are released from islands as they reconnect with the macro-scale field of the corona or magnetosphere. The characteristic width of the released energetic electron streams correspond to the width of the reconnection dissipation region. Thus, energetic electrons do not propagate away from the reconnection site in the corona as a single large-scale front but as a filamentary web. As a result, the return current problem is transformed: the narrow filaments of energetic particles propagate parallel to the magnetic field as kinetic Alfven waves with propagation speeds comparable to the thermal velocity of the energetic particles. Simple estimates suggest that the conversion of particle to kinetic Alfven wave energy is efficient so that the wave and particle energy propagates together as a radiation front from the corona toward the solar surface. The structure and dynamics of this radiation front are being explored.
DE: 7514 Energetic particles (2114)
DE: 7519 Flares
DE: 7526 Magnetic reconnection (2723, 7835)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting