LARGE MACH NUMBER ION-ACOUSTIC RAREFACTIVE SOLITARY WAVES FOR A 2 ELECTRON-TEMPERATURE WARM ION-PLASMA

An exact analytical form of Sagdeev pseudopotential has been derived f or a two electron temperature warm ion plasma, from which ion acoustic rarefactive solitary wave solutions could be investigated for a wide range of different plasma parameters, viz., ion temperature (sigma), c old to hot electron temperature ratio (beta), and initial cold electro n concentration (mu). Explicitly large Mach numbers have; been obtaine d for increasing hot to cold electron temperature ratios, and an analy tical condition for the upper bound of the Mach number has been derive d for such a rarefactive solitary wave. It is found that the width of these waves obey Korteweg-de Vries soliton-type behavior only for smal l amplitudes (i.e., e phi/T-eff<1) while for large amplitudes, the wid th of the rarefactive solitary waves increases with increasing amplitu de. (C) 1996 American Institute of Physics.