Title: Simulation studies of the interaction of laser radiation with additively manufactured foams

Abstract

The interaction of laser radiation with foams of various porosities and low densities has been the subject of several numerical and experimental studies. In all cases, the modeling of low-Z under-dense foams as uniform gases of equivalent average density using standard radiation-hydrodynamics codes has resulted in heat-front velocities that are considerably faster than those observed experimentally. It has been theoretically conjectured that this difference may be attributed to the breakdown of the foam’s morphology, leading to a dynamics of filament expansion where the ion and electron energy partitions are significantly different from those calculated using the uniform gas model. We found that 3D computer simulations employing a disconnected representation of the foam’s microstructure which allowed for the dynamics of foam element heating, expansion, and stagnation largely supported the theoretical picture. Simulations using this model for laser experiments on under-dense 2 mg cc^-1 SiO₂ aerogel foams reproduced the experimental data fairly well. We used the validated model in simulations of low-density structured foam-like materials (produced via additive manufacturing) with a variety of morphologies. We found that the log-pile configurations were consistent with the analytical propagation model of Gus’kov et al. Further validation of the model was obtained by simulating experiments performedmore » at the Jupiter Laser Facility using the log-pile and octet-truss foam morphologies. Simulations of the foam-laser interaction using a wave propagation code showed that the microstructure was able to enhance stimulated Brillouin scattering (SBS) by concentrating the light energy into density holes. In turn, this promotes laser filamentation, reducing SBS and bringing the predicted values closer to the experimental data.« less

Authors:

Milovich, J. L.  ^[1];

• Search DOE PAGES for author "Milovich, J. L."
• Search DOE PAGES for ORCID "0000-0002-9762-3591"

Jones, O. S.  ^[1];

• Search DOE PAGES for author "Jones, O. S."
• Search DOE PAGES for ORCID "0000-0002-0372-7657"

Berger, R. L. ^[1]; Kemp, G. E. ^[1]; Oakdale, J. S. ^[1]; Biener, J. ^[1]; Belyaev, M. A. ^[1]; Mariscal, D. A. ^[1]; Langer, S. ^[1]; Sterne, P. A. ^[1]; Sepke, S. ^[1]; Stadermann, M. ^[1]

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+ Show Author Affiliations

1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Publication Date:

Thu Apr 01 00:00:00 EDT 2021

Research Org.:

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program

OSTI Identifier:

1845209

Report Number(s):

LLNL-JRNL-813120
Journal ID: ISSN 0741-3335; 1018790; TRN: US2302417

Grant/Contract Number:  

AC52-07NA27344

Resource Type:

Accepted Manuscript

Journal Name:

Plasma Physics and Controlled Fusion

Additional Journal Information:

Journal Volume: 63; Journal Issue: 5; Journal ID: ISSN 0741-3335

Publisher:

IOP Science

Country of Publication:

United States

Language:

English

Subject:

70 PLASMA PHYSICS AND FUSION TECHNOLOGY; laser plasma interaction; additive manufactured foams; NIF