Particle simulation of the magnetic reconnection with adaptive mesh refinement method

Summary form only given. We have developed a new code combining a full particle electromagnetic code with an adaptive mesh refinement (AMR) method in which a grid is divided into subgrids (four subgrids in a 2D code) to achieve a high spatial resolution in an efficient manner (Fujimoto, K and Machida, S., 2004). By applying this code to the magnetic reconnection in the terrestrial magnetotail with a Harris-type thin current sheet, we study the formation and development of the magnetic reconnection and the process that breaks the frozen-in condition of the electrons to make the magnetic fields merge. We find the contribution of the electron inertia and also the divergence of the electron pressure tensor in balancing with the duskward electric field at the center of the reconnection, i.e., the magnetic neutral line, as is already known. In the downstream region just outside the neutral line, we found significant electron heating. The distribution function of electrons is not isotropic but has an anisotropic distribution in which the electrons are more heated in the perpendicular direction. This result is consistent with our previous study (Fujimoto and Machida, 2003) in which electrons are perpendicularly heated by the waves excited by electron cyclotron drift instability when the bulk flow velocity of electrons far exceeds the electron thermal velocity. We report various types of distribution functions of ions and electrons found in the simulation system and compare the model with spacecraft observations.