Saturation of the Decay Instability for Comparable Electronic and Ion Temperatures

Abstract

We present a model for the nonlinear evolution of the electron-plasma ion-acoustic decay instability when the ratio of electron and ion temperatures is of order 1. Ion nonlinear Landau damping is found to be the dominant saturation mechanism. We calculate the saturated spectral intensity and pump absorption coefficient. An estimate is given of the energy that the enhanced fluctuations absorb from an electromagnetic wave incident on an inhomogeneous plasma.