HR: 11:45h
AN: SP22A-05 [Abstracts]
TI: Self Consistent Modeling of Current Sheet Structure and Transport Processes
AU: * Goodman, M L
EM: mgoodman@isr.us
AF: Institute for Scientific Research, Inc., 2500 Fairmont Avenue - Suite 734, Fairmont, WV 26555-2720 United States
AB:
A simple magnetohydrodynamic (MHD) model of a fully ionized, collision dominated plasma that includes the electrical
conductivity and thermoelectric tensors in Ohm's law is used
to generate current sheet solutions that, where the assumption
of full ionization is valid, are characterized by ranges of
temperature, density, magnetic field strength, and flow speed
that correspond to those of the transition region and corona.
The electrical conductivity and thermoelectric tensors are
functions of temperature, number density, and magnetic field
strength.
The model contains a prescribed sheared magnetic field with a
characteristic length scale L. The characteristic sheet
width is 2L, but the temperature has transition region or
coronal values only within a central plasma sheet (CPS) that
has a width one or more orders of magnitude smaller than 2L.
The CPS is essentially the diffusion region.
The heating rate per unit mass, and the flow speed in the CPS
are orders of magnitude larger, and the density is orders of
magnitude smaller than in the surrounding plasma. The heating
rate per unit volume is a maximum in the CPS, and falls off
steadily outside the CPS. The heating is driven almost
entirely by the convection electric field. The current density
and heating rate each consist of a thermoelectric component
driven by the temperature gradient, and a conduction component driven by
the center of mass electric field. These components largely
cancel one another, yielding a total current density and
heating rate that are orders of magnitude smaller than either
of their components. This suggests that thermoelectric effects
are important in determing current sheet structure.
This work was supported by NSF grant ATM-0242820 to the Institute for
Scientific Research.
DE: 7509 Corona
DE: 7546 Transition region
DE: 7827 Kinetic and MHD theory
DE: 7835 Magnetic reconnection
DE: 7859 Transport processes
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly