2 ION FLUID NUMERICAL INVESTIGATIONS OF SOLAR-WIND GAS RELEASES

A two ion species system of fluid equations is used to investigate mec hanisms responsible for transverse accelerations of plasma releases in to high Mach number flows, such as that of the December 1984 Active Ma gnetospheric Particle Tracer Experiment (AMPTE) release of barium ions into the solar wind. We extend previous work in single ion species sy stems by developing a set of modified MHD equations which incorporates both the unmagnetized nature of the released ions and the interaction s of the two ion fluids. An analysis of this system of equations sugge sts two mechanisms that could cause transverse shifts of the plasma re lease. One of these is based on a magnetic drift wave, the other on a hybrid cyclotron mode. Numerical simulations produce clearly observabl e shifts in the case of each mechanism. The modified two-fluid MHD equ ations, simulation results, and physical mechanisms are discussed, and their relevance to the AMPTE barium release is examined.