Ogden Jones | 17-ERD-118
Foam materials are starting to find application in laser-heated hohlraums used to drive inertial confinement fusion (ICF) implosions. The disparate scales of the solid foam elements (nanometer scale) compared to the typical problem scale (millimeter scale) make it expensive to resolve the individual foam elements in hydrodynamic calculations.
In this project we developed two new models for treating foam materials: (1) a three-dimensional hydrodynamic model that treats the foam as bits of pre-expanded solid material separated by voids; and (2) a subgrid model that captures the essential physics of laser-heated foams without requiring resolution of the individual solid elements. We also explored the microphysics of the transition from interpenetrating kinetic behavior to fully-collisional fluid-like behavior during the early time heating and expansion of foam elements through a combination of single-fluid and multifluid hydrodynamics calculations and particle-in-cell calculations. The model was benchmarked against these calculations and against experimental data on laser-heated chemical and additive-manufactured (AM) foams. Since there was no existing data on laser-heated AM foams, we performed the first experiments on such foams at Lawrence Livermore National Laboratory's Jupiter Laser Facility. Samples of three different types of printed AM foams were heated using a single 0.5-micrometer laser beam. The foam densities ranged from 10 to 100 milligrams per cubic centimeter (supercritical for 0.5-micrometer light). This benchmarked subgrid foam model is a new capability that should allow routine calculation of ICF designs using foam elements, potentially opening up a new design space.
This work contributed to advancements in Livermore's core competencies in high-energy-density (HED) science and advanced materials and manufacturing. Foam materials may be particularly useful for ICF applications, where their use has been limited in part by modeling difficulties. The new foam material modeling techniques developed in this project should enable more routine use of foams in HED applications. This was an important first step in showing practical applications in HED science and ICF for these new materials.
Publications, Presentations, and Patents
Belyaev, M. A., et al. 2018a. "Energy-conserving model of laser propagation and heating in a subcritical foam." Anomalous Absorption, Bar Harbor, ME, June 2018. LLNL-PRES-754460
——— 2018b. "Laser propagation in a subcritical foam: Ion and electron heating." Physics of Plasmas 25, 12. doi:10.1063/1.5050531. LLNL-JRNL-760854
——— 2019a. "Subgrid Model of Laser Propagation and Heating in a Foam." 61st Annual Meeting of the American Physical Society Division of Plasma Physics, Fort Lauderdale FL, October 2019. LLNL-ABS-779901
——— 2019b. "Subgrid model of laser-foam interaction with experimental comparison to SiO2 aerogels." Anomalous Absorption, Telluride, CO, June 2019. LLNL-PRES-777197
Berger, R., et al. 2019. "Multi-dimensional Simulations of Interpenetrating Plasmas." Anomalous Absorption, Telluride, CO. LLNL-ABS-772508
Jones, O. S., et al. 2019. "Development of computational models for additive manufactured and aerogel foams for hohlraum applications." International Conference on Inertial Fusion Sciences and Applications, Osaka, Japan, September 2019. LLNL-PRES-790698
Langer, S., et al. 2018. "Simulating laser ablation of foam filaments using HYDRA." Anomalous Absorption, Bar Harbor, ME June 2018. LLNL-CONF-754261
——— 2019. "HYDRA Simulations of Laser-heated Foams." Anomalous Absorption, Telluride, CO, June 2019. LLNL-PRES-777454
Milovich, J. L., et al. 2018a. "Simulation Studies of the Interaction of Laser radiation with Additively Manufactured Foams." 45th European Physical Society Conference on Plasma Physics, Prague, Czech Republic, July 2018. LLNL-PRES-753673
——— 2018b. "Simulation Studies of laser-irradiated additive-manufactured foams." 60th Annual Meeting of the American Physical Society Division of Plasma Physics, Portland, OR, November 2018. LLNL-ABS-753147
——— 2019. "Experiments and Simulations of laser-irradiated additive-manufactured foams." 46th European Physical Society Conference on Plasma Physics, Milan, Italy, July 2019. LLNL-PRES-779892