NONINTEGRABLE INTERACTION OF ION-ACOUSTIC AND ELECTROMAGNETIC-WAVES IN A PLASMA

In this paper we reexamine the one-dimensional interaction of electrom agnetic and ion acoustic waves in a plasma. Our model is similar to on e solved by Rao et al. [Phys. Fluids 26, 2488 (1983)] under a number o f analytical approximations. Here we perform a numerical investigation to examine the stability of the model. We find that for slightly over dense plasmas, the propagation of stable solitary modes can occur in a n adiabatic regime where the ion acoustic electric-field potential is enslaved to the electromagnetic field of a laser. However, if the lase r intensity or plasma density increases or the laser frequency decreas es, the adiabatic regime loses stability via a transition to chaos. Di fferent asymptotic states are attained when the adiabatic regime no lo nger exists. In these states the plasma becomes rarefied and the laser field tends to behave like a vacuum field.