Hybrid Particle-in-Cell Simulations of Stimulated Brillouin Scattering Including Ion-Ion Collisions

It is shown that ion-ion collisions can have a very important effect on stimulated Brillouin scattering of laser light in high-Z plasmas, such as those near the wall of a laser-irradiated hohlraum. We report the first hybrid particle-in-cell simulations of stimulated Brillouin scattering including these collisions. Collisions can play a vital role in the nonlinear state by maintaining a negative slope to the ion distribution function, which greatly distorts and even flattens near the ion wave phase velocity in collisionless simulations. Other collisional effects are also illustrated.