Particle-in-Cell Modeling of Laser--Plasma Interactions in Three Dimensions

In the direct-drive method of inertial confinement fusion, the laser--plasma interactions (LPI's) near quarter-critical density are very important for laser absorption and fast-electron generation.\footnote{J. F. Myatt \textit{et al}., Phys. Plasmas \textbf{20}, 052705 (2013).} Three-dimensional simulations with the particle-in-cell (PIC) code \textit{OSIRIS} have allowed us to study different parametric instabilities including two-plasmon decay, stimulated Raman scattering, and stimulated Brillouin scattering. These instabilities may coexist and interact in the region near quarter-critical density. The spectra of forward-going and backward-going scattered light and fast electrons in two-dimensional and three-dimensional PIC simulations have been studied. Characteristics of LPI driven by a plane-wave laser and by an incoherent laser beam are compared. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.