Mulit-ion plasmas in astrophysics

An isothermal hydrodynamic model of the motions of a multi-ion plasma in a gravitational field is developed and the properties of the flow are discussed for the case of major astrophysical interest in which the gas undergoes a subsonic-supersonic transition. It is shown that the existence of critical points thorough which the plasma has to pass will determine a large number of the plasma parameters, especially the temperature of the minor ions. The equation of motion of a two ion gas (hydrogen-helium) are solved numerically and yield the interesting result that the bulk velocity of the plasma constituents are not equal at 1 AU.Operated by the Association of Universities for Research in Astronomy, under contract with the National Science Foundation.