Modulated ion acoustic waves in a plasma with Cairns-Gurevich distribution

Abstract

The amplitude modulation of ion acoustic envelope solitary waves in the presence of Cairns-Gurevich distributed electrons has been investigated. Using a reductive perturbation technique, a modified nonlinear Schrödinger equation has been derived. The modulational instability (MI) and its dependence on the system physical parameters and the combined effects of trapped and nonthermal electrons have been analyzed. It is found that the MI maximum growth rate increases (decreases) as the nonthermality (trapping) parameter increases. The present results could be applicable in explaining the basic features of localized electrostatic disturbance in space observations such as the solar energetic particle flows in interplanetary space and the energetic particle events in the Earth's magnetosphere and also in the laser plasma interaction.