No description available.

Vlasov-Maxwell equilibria are characterised by the self-consistent descriptions of the steady-states of collisionless plasmas in particle phase-space, and balanced macroscopic forces. We study the theory of Vlasov-Maxwell equilibria in one spatial dimension, as well as its application to current sheet and flux tube models. The ‘inverse problem' is that of determining a Vlasov-Maxwell equilibrium distribution function self-consistent with a given magnetic field. We develop the theory of inversion using expansions in Hermite polynomial functions of the canonical momenta. Sufficient conditions for the convergence of a Hermite expansion are found, given a pressure tensor. For large classes of DFs, we prove that non-negativity of the distribution function is contingent on the magnetisation of the plasma, and make conjectures for all classes. The inverse problem is considered for nonlinear ‘force-free Harris sheets'. By applying the Hermite method, we construct new models that can describe sub-unity values of the plasma beta (βpl) for the first time. Whilst analytical convergence is proven for all βpl, numerical convergence is attained for βpl = 0.85, and then βpl = 0.05 after a ‘re-gauging' process. We consider the properties that a pressure tensor must satisfy to be consistent with ‘asymmetric Harris sheets', and construct new examples. It is possible to analytically solve the inverse problem in some cases, but others must be tackled numerically. We present new exact Vlasov-Maxwell equilibria for asymmetric current sheets, which can be written as a sum of shifted Maxwellian distributions. This is ideal for implementations in particle-in-cell simulations. We study the correspondence between the microscopic and macroscopic descriptions of equilibrium in cylindrical geometry, and then attempt to find Vlasov-Maxwell equilibria for the nonlinear force-free ‘Gold-Hoyle' model. However, it is necessary to include a background field, which can be arbitrarily weak if desired. The equilibrium can be electrically non-neutral, depending on the bulk flows.

Title: Structure, Location, and Dynamics of the Magnetopause Author: Kostiantyn Grygorov Department: Department of Surface and Plasma Science Supervisor: Doc. RNDr. Lubomír Přech, Dr., Department of Surface and Plasma Science e-mail address: Prech@mbox.troja.mff.cuni.cz Abstract: The magnetopause is the key region where the collisionless plasma from the Sun penetrates into the Earth's magnetosphere. A transfer of the plasma, momentum, and energy across the magnetopause is highly variable and depends on solar wind conditions, similarly as the magnetopause location. This thesis addresses the solar wind-magnetosphere interaction in two different regions: the dayside equatorial magnetopause and the far magnetotail. In the first part of the thesis, we present a detailed analysis of the interplanetary (IP) shock propa- gation through the solar wind, its impact on the substorm development and its influence on the far magnetotail. We demonstrate that the change of the solar wind VZ component across the shock creates a huge kink that propagates along the tail. The second part of the thesis is devoted to the influence of prolonged intervals of a radial interplanetary magnetic field (IMF) on the dayside magnetopause. The statistical analysis of the equatorial magnetopause shape and location based on THEMIS observations...