COALESCENCE OF 2 PARALLEL CURRENT LOOPS IN A NONRELATIVISTIC ELECTRON-POSITRON PLASMA

The coalescence of two parallel current loops in an electron-positron plasma is investigated by a three-dimensional electromagnetic relativi stic particle code. Instead of mixing uniformly in the dissipation reg ion as observed for current coalescence in an electron-ion plasma, ele ctrons and positrons initially in the loops are driven to move separat ely by the magnetic gradient drift. Redistribution of the current-carr ying electrons and positrons creates new current loops, which coalesce again, if the initial drift velocities remain greater than a critical value after coalescence. It was found that the energy stored in the c urrent loops dissipates gradually through several coalescences. Conseq uently, the electrons and positrons near the current loops are heated through the coalescence. This process is qualitatively different from the explosive energy release during coalescence in an electron-ion pla sma. (C) 1996 American Institute of Physics.