HR: 1340h
AN: SH44A-1724    [Abstracts]
TI: X-line Retreat During Magnetic Reconnection
AU: * Oka, M
EM: mitsuo@ucr.edu
AF: IGPP, UCR, 900 University Avenue, Riverside, CA 92521, United States
AU: Shinohara, I
EM: iku@stp.isas.jaxa.jp
AF: Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai Sagamihara, Kaganawa, 229- 8510, Japan
AU: Fujimoto, M
EM: fujimoto@stp.isas.jaxa.jp
AF: Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai Sagamihara, Kaganawa, 229- 8510, Japan
AB: In many astro- and space- physics situations, we observe energy release processes in vicinities of an obstacle. In the Earth's magnetotail, an Earthward plasma flow hits the magnetosphere which might end up with magnetic field pile-up and/or dipolarization of the magnetosphere. During solar flares, in view of magnetic reconnection model, a downward plasma jet collides with a magnetic flux tube in the lower part of the solar corona. In order to study energy release processes in these situations, we have set up a hard wall (symmetric boundary) to model either dipole magnetic field in the Earth's magnetosphere or magnetic loops in the solar corona. For simplicity, we have neglected any density gradient or magnetic field structures. The initial configuration of the current sheet is therefore of a Harris-type. After initiating magnetic reconnection by a magnetic field perturbation, its time evolution is observed by means of full particle, PIC simulation. The prominent feature in our simulation is a slow motion of the X-point directing away from the wall, which we call `X-line Retreat'. Our preliminary results show retreat speed to be about 0.1 times the Alfven speed measured at the boundaries. In our talk, we will discuss the mechanism and cause of the X-line retreat as well as the structures of the diffusion region. Implication on particle acceleration will also be addressed.
DE: 7835 Magnetic reconnection (2723, 7526)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting