Ion-Trapping Saturation of the Brillouin Instability

Abstract
The ion acoustic wave and harmonics driven by stimulated Brillouin scattering are probed by space- and time-resolved ruby-laser Thomson scattering. Corresponding to the 6% backscatter observed, the ion wave is seen to saturate at (5-10)% amplitude, a level quantitatively predictable from the nonlinear frequency shift caused by ion trapping.