Nonthermal electrons and warm ions effects on oblique modulation of ion-acoustic waves

By using the standard reductive perturbation technique, a nonlinear Schrodinger equation is derived to study the instability of oblique modulation of finite amplitude ion-acoustic waves in an unmagnetized plasma consisting of warm adiabatic ions and nonthermal electrons. The effects of nonthermally distributed electrons on the modulational instability and the solitary structures are investigated. It is found that the presence of nonthermal electrons significantly changes the domain of the modulational instability in the k-theta plane. (C) 2004 American Institute of Physics.