Geometry and Kinetics of Astrophysical Plasmas: A gyrokinetic approach

In the context of astrophysical plasmas, various methods are used in order to study problems such as dissipation of turbulent energy and magnetic reconnection. The use of fluid models allow us to understand macroscopic phenomena, but lacks the dynamics of kinetic physics. On another hand, kinetic models usually consume an enormous amount of computing time. The use of reduced models such as gyrokinetics are foreseen to bridge the gap between the fluid and kinetic approaches. In the present work, we aim to investigate the use of gyrokinetics in two different scenarios. Firstly we are going to consistently derive a hybrid hamiltonian field theoretical system, based on the lagragian formulation of a symplectic two-form. In this system, ions are treated fully kinetically, and electrons gyrokinetically. With this model, we wish to develop a cost effective kinetic computational framework. The second aspect of the present work addresses a well known problem in space physics, namely magnetic reconnection with guide field. We start with a gyrokinetic analysis using the code GENE. Firstly we analyze the dynamics of the parallel electric field and reconnection rate on the X point, and proceed with benchmarking GENE with a fully kinetic PIC code.