Solitons in multi-ion plasmas

In the heliosphere large fluctuations of the magnetic field are sometimes o bserved, especially at shacks (e.g. travelling interplanetary shocks, plane tary bow waves, and shocks related to corotating interaction regions). The large fluctuations very often have an amplitude that reaches easily four or five times the magnitude of the quiet magnetic field. Since the plasma mos tly contains a non-negligible fraction of heavy ions (e.g. helium ions or c ometary water ions), these magnetic field fluctuations are described in ter ms of three-fluid equations. Here electrons, protons and heavy ions are con sidered as separate fluids interacting with themselves by electromagnetic f orces. The three-fluid equations are treated in such a way that we are sear ching for one-dimensional stationary waves. Thus the equations are reduced to a fully nonlinear set of ordinary differential equations. which have bee n evaluated numerically with respect to solitary was es. Subsequently examp les of solitary waves in a electron-proton plasma loaded with 10% He-4(2+) ions are presented. For instance, an enrichment of helium ions is observed within the solitary waves.