Three-dimensional HYDRA simulations of National Ignition Facility targets

TLDR

The authors performed three‑dimensional HYDRA simulations of National Ignition Facility targets, incorporating detailed hohlraum geometry and laser illumination. The simulations show that hohlraum wall motion remains highly axisymmetric, laser light traverses the entrance hole as required, energetics agree with axisymmetric models, and hydrodynamic instabilities evolve into a weakly nonlinear regime without anomalous low‑mode growth. Citation: M.

Abstract

The performance of a targets designed for the National Ignition Facility (NIF) are simulated in three dimensions using the HYDRA multiphysics radiation hydrodynamics code. [M. Marinak et al., Phys. Plasmas 5, 1125 (1998)] In simulations of a cylindrical NIF hohlraum that include an imploding capsule, all relevant hohlraum features and the detailed laser illumination pattern, the motion of the wall material inside the hohlraum shows a high degree of axisymmetry. Laser light is able to propagate through the entrance hole for the required duration of the pulse. Gross hohlraum energetics mirror the results from an axisymmetric simulation. A NIF capsule simulation resolved the full spectrum of the most dangerous modes that grow from surface roughness. Hydrodynamic instabilities evolve into the weakly nonlinear regime. There is no evidence of anomalous low mode growth driven by nonlinear mode coupling.