Fast collisionless magnetic reconnection: Fluid regime and kinetic effects

Collisionless magnetic field line reconnection exhibits important similarities under widely different physical conditions. ranging from the magnetohydrodynamic regime, of interest for space and high temperature magnetically confined plasmas, to the electron-magnetohydrodynamic regime, of interest for the interaction of ultraintense, ultrashort laser pulses with a plasma. Analytical and numerical results are presented that illustrate the nonlinear evolution of the reconnection instability in a two dimensional configuration with a neutral line in fluid and in kinetic plasma regimes. The importance of plasma anisotropy is stressed for the case of laser plasma interaction.