HR: 15:05h
AN: SH32B-06    [PDF]
TI: The Effect of the Guide Field on the Developement of Turbulence in 3-D Reconnection
AU: * Swisdak, M
EM: swisdak@glue.umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742 United States
AU: McIlhargey, J
EM: jmci1@umbc.edu
AF: UMBC, Department of Physics, Baltimore, MD 21250 United States
AU: Drake, J F
EM: drake@glue.umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742 United States
AB: Recent 3-D simulations of magnetic reconnection have shown that the presence of a guide field (a component perpendicular to the reconnection plane) strongly effects the development of turbulence. With no guide field the inflowing electrons become demagnetized inside the current layer, leading to an effective heating that suppresses shear flow instabilities even in the limit of small asymptotic temperature [Zeiler et al., 2001]. Drake et al. (2003) showed that a large guide field magnetizes the electrons and stops this thermalization, allowing the Buneman instability to drive turbulence (in the form of electron holes) at the X-line and along the separatrices. We show that, in fact, quite small values of the guide field are sufficient to keep the electrons magnetized and hence allow the development of turbulence. An examination of the distribution functions at the X-line of a series of 2-D simulations shows a clear transition when the guide field is about one-tenth the asymptotic reconnection field, a result consistent with both analytic arguments and further 3-D simulations. These results imply that electron hole turbulence may be ubiquitous at reconnection sites in nature.
DE: 7807 Charged particle motion and acceleration
DE: 7835 Magnetic reconnection
DE: 7863 Turbulence
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting