NONLINEAR KINETIC SIMULATIONS OF STIMULATED BRILLOUIN-SCATTERING

Numerical simulation results of stimulated Brillouin scattering (SBS) using HERCULES [H. X. Vu, J. Comput. Phys. 124, 417 (1996)], an adiaba tic fluid-electron particle-in-cell (PIC) code, are presented. The res ults of these PIC simulations are compared against fluid simulations, and good agreement is obtained for sufficiently weak laser intensities . When the laser intensity is sufficiently strong for ion trapping to be significant, PIC and fluid simulations differ substantially. The tr apping time and nonlinear frequency shift obtained in the PIC simulati ons are in good agreement with analytical predictions. The SBS reflect ivity is shown to be very sensitive to frequency mismatch between the light wave used to seed the instability and the incident laser.