Modeling the Backscatter and Transmitted Light of High Power Smoothed Beam with pF3D, a Massively parallel Laser Plasma Interaction Code

摘要

Using the three-dimensional wave propagation code, F3D(Berger et al., Phys. Fluids B 5,2243 (1993), Berger et al., Phys. Plasmas 5,4337(1998)), and the massively parallel version pF3D, (Still et al. Phys. Plasmas 7 (2000)), we have computed the transmitted and reflected light for laser and plasma conditions in experiments that simulated ignition hohlraum conditions. The frequency spectrum and the wavenumber spectrum of the transmitted light are calculated and used to identify the relative contributions of stimulated forward Brillouin and self-focusing in hydrocarbon-filled balloons, commonly called gasbags. The effect of beam smoothing, smoothing by spectral dispersion (SSD) and polarization smoothing (PS), on the stimulated Brillouin backscatter (SBS) from Scale-1 NOVA hohlraums was simulated with the use nonlinear saturation models that limit the amplitude of the driven acoustic waves.