1½ D computer simulations have been performed to illustrate the influence of ion dynamics on stimulated Raman scattering in laser irradiated plasmas. A flat density profile has been used. Backward and forward scatter and heated electron distribution have been studied as a function of ion mass and ion temperature. The results show clearly that the lighter the ions, the more inhibited the Raman scatter and associated fast electron production. Futhermore, when ions are cold enough to allow Brillouin scattering release, Raman scatter, as well as associated suprathermal electrons is even more reduced. These observations evidence the complex non-linear coupling of the electron plasma waves driven by the Raman instability and the ion fluctuations which can exist in the plasma.
Stimulated Raman scatter in laser fusion target chambers