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Jan Egedal. Ohia, Obioma Ogonna Chinyerem Massachusetts Institute of Technology. Department of Physics. Massachusetts Institute of Technology. Department of Physics 2015-03-05T15:56:41Z 2015-03-05T15:56:41Z 2014 http://hdl.handle.net/1721.1/95854 903912750 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. 206 pages eng Massachusetts Institute of Technology 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 Physics. Two-fluid simulations of magnetic reconnection with a kinetic closure for the electron pressure anisotropy 2-fluid simulations of magnetic reconnection with a kinetic closure for the electron pressure anisotropy Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="9a37d2eb-e25c-4c2d-8a5e-c91d847534b2"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Two-fluid simulations of magnetic reconnection with a kinetic closure for the electron pressure anisotropy</Title> <Subtitle>2-fluid simulations of magnetic reconnection with a kinetic closure for the electron pressure anisotropy</Subtitle> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2014</PublicationDate> <Authors> <Author> <DisplayName>Ohia, Obioma Ogonna Chinyerem</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Physics.</Keyword> <Abstract>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.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>