Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 189-206). / Magnetic reconnection is a rapid rearrangement of magnetic line topology in a plasma that can allow magnetic energy to heat, drive macroscopic flows, or accelerate particles in space and laboratory plasmas. Though reconnection affects global plasma dynamics, it depends intimately on small-scale electron physics. In weakly-collisional plasmas, electron pressure anisotropy resulting from the electric and magnetic trapping of electrons strongly affects the structure surrounding the electron diffusion region and the electron current layer. Previous fluid models and simulations fail to account for this anisotropy. In this thesis, new equations of state that accurately describe the electron pressure anisotropy in cases of sufficiently strong guide magnetic field are implemented in fluid simulations and are compared to previous fluid models and kinetic simulations. Elongated current layers in the reconnection region, driven, in part, by this pressure anisotropy, appear as part of a self-regulating mechanism of electron pressure anisotropy. The structure depends on plasma parameters, with low guide fields yielding longer layers. / by Obioma Ogonna Chinyerem Ohia. / Ph. D.
| Identifer | oai:union.ndltd.org:MIT/oai:dspace.mit.edu:1721.1/95854 |
| Date | January 2014 |
| Creators | Ohia, Obioma Ogonna Chinyerem |
| Contributors | Jan Egedal., Massachusetts Institute of Technology. Department of Physics., Massachusetts Institute of Technology. Department of Physics. |
| Publisher | Massachusetts Institute of Technology |
| Source Sets | M.I.T. Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 206 pages, application/pdf |
| Rights | M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission., http://dspace.mit.edu/handle/1721.1/7582 |
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