HR: 08:20h
AN: SM51D-02 INVITED    [Abstracts]
TI: Production of energetic electrons and ions during magnetic reconnection
AU: * Drake, J
EM: drake@umd.edu
AF: U.C. Berkeley, SSL 7 Gauss Way, Berkeley, CA 94720-1180, United States
AU: Cassak, P
EM: pcassak@udel.edu
AF: U. Delaware, Department of Physics and Astronomy 217 Sharp Lab, Newark, DE 19716, United States
AU: Phan, T
EM: phan@ssl.berkeley.edu
AF: U.C. Berkeley, SSL 7 Gauss Way, Berkeley, CA 94720-1180, United States
AU: Lin, R
EM: rlin@ssl.berkeley.edu
AF: U.C. Berkeley, SSL 7 Gauss Way, Berkeley, CA 94720-1180, 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
AU: Swisdak, M
EM: swisdak@umd.edu
AF: U. Maryland, IREAP University of Maryland, College Park, MD 20742, United States
AB: Simulations and observations suggest that the formation of magnetic islands is generic to reconnection with a guide field and therefore that particle acceleration in a multi-island environment is of greatest interest. Electrons are accelerated by parallel electric fields localized near the magnetic x-line and through Fermi acceleration in the contracting islands. A contracting island model of electron acceleration has been developed to explain the powerlaw spectra of energetic electrons seen in the Earth's magnetotail and inferred from the solar flare observations. We find that ion acceleration occurs primarily as ions cross from upstream into the Alfvenic outflow jet. Depending on the strength of the guide field, protons and higher mass particles behave like pickup particles in that they abruptly cross a narrow boundary layer and find themselves in a region of Alfvenic outflow. Their motion then mimics that of a classic pickup ion, gaining an Alfvenic ExB flow in the jet and a thermal speed close to the Alfven speed. The resulting ion energy is therefore proportional to mass as in many of the solar energetic particle observations. Preliminary analysis of Wind in-situ observations of solar wind reconnection exhausts supports this picture. A model of solar energetic ion production based on multiple encounters with reconnection exhausts is being pursued.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7835 Magnetic reconnection (2723, 7526)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting