Propagation of solitary waves in a two ion species plasma with finite ion temperature

Using a Korteweg-de Vries equation the author studies the propagation of ion acoustic solitary waves in a two ion species plasma. As the dispersion relation presents two acoustic branches with quite different phase velocities, two types of soliton can propagate: the slow one which is subsonic with respect to one ion mode and supersonic to the other, has greater amplitude and smaller width than the fast one.