Effects of Electron-Ion Collisions on Stimulated Raman Backward Scattering Under Different Electron Densities

Effect of electron-ion collision on stimulated Raman backward scattering (SRBS) spectrum are investigated by numerical simulations. In the given parameters and plasma condition, the growth rates of SRBS are found to strongly depend on the electron density, and the gap in the SRBS spectrum corresponding to the high electron density could be explained by the collisional damping. In the low density region, a much higher Landau damping estimated by the linear theory makes the collisional damping negligible. However, the present results show that, collisions play a even more important role than known in the linear theory.