Abstract:
In this thesis, we will deal with an active area of theoretical research in astrophysical plasma physics, namely with the so called magnetic reconnection (MGR). This phenomenon is important from microphysics point of view, and from the wide range of its applications. The description of MGR is done in the frame work of the magnetohydrodynamics (briefly: MHD). However it cannot be initiated without including a mechanism of dissipation or resistivity. Applying the resistive MHD approach to MGR is a challenging task but it is worth doing, since MGR is important for understanding several phenomena, in particular solar flares, heating of the solar corona from which the solar wind originates. In addition, MGR plays a decisive role in understanding the interaction of the solar wind with the Earth’s magnetosphere leading to geomagnetic storms, and to the formation of the auroras. In this work, we explore the effect of resistivity leading to dissipation and to the creation of a diffusive region in which a tremendous magnetic energy is released. While the present approach does not describe the MGR consistently, it is aim at illustrating the role of resistivity in the whole process of MGR. For this aim we show many results of modern numerical simulations which are unavoidable, since analytical solutions of the MHD equations are not possible. We show that MGR process takes place only if resistivity exists. However, resistivity does not seem to be effective when its constant through time and space. We then show through studying basic physical variables that contribute in MGR that increasing resistivity and changing dimensions of initial current sheet accelerates reconnection of magnetic field lines inside the diffusion region, so fast reconnection mechanism can be realized. Conversion of magnetic energy to heat and kinetic energy is also demonstrated leading to acceleration and heating of solar plasma particles.
Description:
Thesis. M.S. American University of Beirut. Department of Physics, 2017. T:6703.$Advisor : Dr. Mounib El Eid, Professor, Physics ; Members of Committee : Dr. Michel Kazan, Professor, Physics ; Dr. Marwan Darwish, Professor, Mechanical Engineering.
Includes bibliographical references (leaves 48-49)