Inverse bremsstrahlung stabilization of noise in the generation of ultrashort intense pulses by backward Raman amplification

The inverse bremsstrahlung heating of the electrons by the pump laser beam was described. It was used to introduce beneficial time-varying electron temperature gradients along the pump propagation direction. The temperature increase with time caused the linear Landau damping of the Langmuir wave to increase with time, resulting in the decrease in the growth rate of stimulated Raman scatter. The results show that as the temperature is proportional to the charge state, Z, helium or hydrogen-helium mixtures increases the Landau damping.