Nonlinear saturation of stimulated Brillouin scattering for long time scales

The nonlinear saturation of stimulated Brillouin scattering (SBS) in long beryllium plasmas (500 μm) and for long time (500 ps) is studied in detail through well-diagnosed one-dimensional (1D) hybrid particle-in-cell (PIC) simulations done using BZOHAR [B. I. Cohen, B. F. Lasinski, A. B. Langdon, and E. A. Williams, Phys. Plasmas 4, 956 (1997)]. Under conditions of interest, when the linear gain associated with the SBS growth is large, it is shown that following a first phase of large and bursty SBS reflectivity, SBS is suppressed by a self-induced spatial detuning due to inhomogeneous modifications of the (locally averaged) ion distribution function. This nonlinear evolution was observed over a range of laser intensities and plasma parameters.