Magnetic field energy dissipation due to particle trapping in a force-freeconfiguration of collisionless pair plasmas - art. no. 046408

It is shown by using a two-dimensional, fully relativistic, electromagnetic particle-in-cell simulation code that a force-free magnetic configuration in collisionless, electron-positron (pair) plasmas becomes unstable against current-driven Buneman instability and subsequently there occurs a strong magnetic field energy dissipation associated with collisionless magnetic re connection, which can be driven by particle trapping due to two-dimensional electric potentials remaining in the nonlinear stage of the initial curren t-driven Buneman instability. About 43% of the initial magnetic field energ y dissipates and is transformed to plasma heating as well as high-energy pa rticle production. The energy spectrum in the high-energy region is given b y an exponential type with two temperatures. We also show the simulation re sults for the electron-ion plasma to compare the effect of the mass ratio o f the electron and proton.