New type of soliton in Bi‐ion plasmas and possible implications

It is well known that the addition of a second ion population into a proton‐electron plasma gives rise to new low‐frequency wave modes. Here we investigate stationary structures streaming with sub‐fast speed in such a bi‐ion plasma. It is shown that a new type of stationary structure occurs as result of mode splitting effects caused by the second ion population. These so‐called ‘oscillitons' are characterized by an oscillating spatial structure superimposed on the spatial growth or decay associated with the usual single‐ion solitons. Examples of the solution of the full non‐linear equations describing stationary bi‐ion flows are given which show that ‘oscillitons' may contribute to a better understanding of diverse low‐frequency phenomena observed in the mass loaded plasma environments of Mars, Jupiter and comets.