Simulation studies of laser-irradiated additive-manufactured foams*

In the indirect drive approach to inertial confinement fusion a low-Z shell containing DT fuel is compressed by x-rays produced by a laser-heated high-Z surrounding enclosure (hohlraum).   The motion of the hohlraum walls introduces drive symmetry swings that may degrade the capsule performance.  In low-density gas-filled hohlraums (currently the focus of ignition experiments), wall motion may completely or partially inhibit the propagation of the laser beams, especially those depositing the energy at the mid-plane of the hohlraum.  To mitigate this behavior new hohlraum designs are using low-density foams as a substitute for high-density gas fills. However, standard modelling of foams has shown significant disagreement with experimental observations [1].  We show that using modern computer architectures (multi-processors) coupled to a simple statistical representation of a foam goes a long way to bridging the modelling disparities.  Additional benefit can be leveraged from the use of structured foams produced by additive manufacturing (AM). We survey a variety of AM foam configurations to find an optimal design for hohlraum experiments. 

[1] S.Y. Gus’kov et al., Quantum Electron., 24 696 (1997).