Forbidden regions in ion temperatures for ion acoustic compressive solitary waves for a plasma with two electron temperatures

It is observed that, there exist certain forbidden regions in ion temperatures, for a compressive solitary wave, which do not have any solitary wave solution. These regions exist for a two- as well as a single-electron temperature plasma. A physical model is proposed to explain this phenomenon on the basis of the energy relation. It is revealed that a one-dimensional single warm ion fluid consists of two distinct energy components. A simple algebraic condition has been derived which expresses the balance between nonlinearity and dispersion for a fully nonlinear solitary wave. It shows that both the nonlinearity and dispersion decrease with increasing ion temperature and that the balance condition is well maintained for the whole spectrum of solitary wave solutions. copyright 1997 American Institute of Physics