HED Physics Target Fabrication By Additive Manufacturing

HED Physics Target Fabrication by AdditiveManufacturingTarget Fabrication Meeting 2017Presenter: James OakdaleMarch 12-16, 2017LLNL-PRES-725758This work was performed under the auspices of the U.S. Department of Energy by Lawrence LivermoreNational Laboratory under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

Accelerated Development of MultiscaleMaterials: Project TeamLDRD 15-ERD-019PI: Juergen BienerHEDRay Smith, Suzanne J. M. Ali, Hye-Sook. Park, Shon Prisbrey, Peter AmendtTomographyJean-Baptiste Forien, L. B. Bayu Aji, Trevor M. Willey, Tony van BuurenTarget FabricationCarol Davis, Richard SeuglingMaterials/TemplatingMonika Biener, J. Ye, Sung-Ho Kim, Patrick G. Campbell, Swetha Chandrasekaran, Marcus Worsley,Ted F. Baumann.Additive ManufacturingWilliam L. Smith, Mathew Worthington, Chris. M. Spadaccini2LLNL-PRES-xxxxxx

Advantages of Additive Manufacturing (AM) forTarget Fabrication Needs: Low Density Foam Materials.— Mitigate hydro-instability growth. Today’s Technology: Chemical synthesis of lowdensity bulk materials followed by precisionmachining and assembly.density Benefits of AM: Complexity is free. Tailored density profiles. Rapid on-demand and tooling-free fabrication. Cost-Saving. Reproducibility.Cross-section of a stepped density foamCurrent technologydepthdensity— Precision Machining is time-consuming and expensive.— Only Stepped Density Profiles can be realized.— Low throughput.AM EnabledDeterministic andtunable density gradientdepthCan AM Meet the various Target Fabrication Challenges?3LLNL-PRES-xxxxxx

Direct Laser Writing via Two PhotonPolymerization (DLW-TPP) AM Candidate: DLW-TPP— Here, a tightly focused, femtosecond pulsed laser (TM/cm2) drives non-linearmultiphoton absorption processes in photosensitive molecules, which in turn, initiatelocal polymerization chemistries. Sub-diffraction Limit Feature Size Resolution— Reliable fabrication of 200 nm. Commercial Nanoscribe Printer142 nm400 nmAdv. Mater. 2012, 24, 2710–2714AIP ADVANCES 2015, 5, 0307014LLNL-PRES-xxxxxx

AM Foams Through Stitching and Lego BlockAssembly Galvo-mirror Laser Scanning: 10 mm/s print speeds, 15 nm accuracy.— High numerical aperture (NA 1.3) objectives provide the best resolutions, but offer restrictedwriting areas due to various optical distortions and vignetting (NA 1.4 120 x 120 µm2)— Log-pile architectures maximize time spent galvo printing.Taller Blocks ( 50 µm2)5 µmXY StitchingCured material can clipthe path of the laserThinner Blocks ( 20 µm2)Oakdale et al. SubmittedBrickwork Pattern100 µmShadowing effects10 µm5LLNL-PRES-xxxxxx

Engineered Density ProfilesDensity (g/cc) Desired Densities can be easily tunedby adjusting the pitch (XY line spacing)within the log pile architecture.100.90.7Density (g/cc)Measured Densities0.4507510020 µm0.60.525Distance (thickness, µm)Predicted Densities300 nm (line Width)400 nm0.8Density (g/cc)0.60.50.40.30.20.100.92 TW/cm2 1.240.30.20.60.50.40.30.20.1000.1255075100Distance (thickness, µm)0012Oakdale et al. Submitted3456Pitch (µm)7891020 µm6LLNL-PRES-xxxxxx

Ramp-Drive Material Strength Tests at Omega5 µmLiF, 1 mmGap, 400 umTarget (Al, 3-10 um)5 µmhalfraum350 nmBe, 25um12% BrCH, 180umAM Foam Target design for experiments at Omega required:— Planar, 1.5 mm diameter, 100-150 µm thick foams.— Single Density 50 mg/cc, with minimized pore size.— Performance comparison to carbon aerogels.Oakdale et al. Submitted7LLNL-PRES-xxxxxx

Ramp-Drive Material Strength Tests at OmegaVISAR 1Good agreement between predictedand measured target velocitys79456s79459s7946779456: 95mg/cc79459: 90mg/cc Desired Density 50 mg/cc Delivered Density 70 mg/cc Simulated Density 90 mg/ccOakdale et al. Submitted8LLNL-PRES-xxxxxx

AM Foam Tomography Tomographic analysis clearly revealed the designed stitching pattern.200 µm5 µmStitching induced defects20 µmALS Beamline 8.3.2 is a Synchrotron-based Hard X-ray source, with resolution of approximately 1 micron per pixel.9LLNL-PRES-xxxxxx

2D VISAR Experiments The resulting 2D VISAR non-fringe image shows a grid pattern consistent withour stitching pattern.-300-200200300400s81707 imgOakdale et al. Submitted400300200Distance (um)1000-100-200-300-400-400Distance (um)-100010010LLNL-PRES-xxxxxx

Physically Constrained Stitching Replace square stitching blocks withjigsaw shaped blocks. Repeat 2D VISAR experiments:CRF30 µmStitching PeriodicityTomographic SliceAM Foam11LLNL-PRES-xxxxxx

Interdigitated NanostitchTM Interdigitated Stitching: Blocks are printed within already printed blocks along stitchseams. The pitch (XY line spacing) of each individual block is set at twice the desired pitch,thereby arriving at appropriate density values in the areas of block overlap.10 µmOakdale et al. SubmittedALS Beamline 8.3.2 is a Synchrotron-based Hard X-ray source, with resolution of approximately 1 micron per pixel.12LLNL-PRES-xxxxxx

Interdigitated 2D VISAR Experiments Interdigitated Nanostitchremoved previouslyobserved stitching inducedartifacts. AM foams preform similarto CRF foams.Step InterfaceStep InterfaceNo FoamAM FoamStep InterfaceCRF FoamAM Foam 2 (s84390)AM Foam 2 (s84390) REFEmpty (s84387)Empty (s84387) REFCRF (s84386)CRF (s84386) REFNo FoamAM FoamCRF FoamVelocity-Density .060.070.060.070.1(100 µm) (50 µm) (33 µm) (25 µm) (20 µm) (17 µm) (14 µm) (12.5 µm) (11 µm) (10 µm)Oakdale et al. Submitted-1Spatial Frequency (um )13LLNL-PRES-xxxxxx

Foam Lined Hohlraums using Sacrificial AMFoam Templates. Needs: Foam liners inprove energy efficiency and symmetry control. Design: Thin (200 µm), sub 50 mg/cc, mid/high Z material hohlraum liner.without foam liner AM Liner Tooling-free fabrication no debris. Tunable foam features: size, density profile, composition. Rapid on-demand fabrication/reproducibility.300 µmWith foam liner8 µm14LLNL-PRES-xxxxxx

AM Hohlraum Liners Robust liners required in-house resin development.Commercial ResinMW 56Structural Collapse Hohlraum Liner Insertion:15LLNL-PRES-xxxxxx

Templating AM Foams. Templating Improved material properties, weight reduction, mid/high Z.— Atomic Layer Deposition (ALD): lumina, tantalum oxide, etc. (M. Biener).— Electroless Nickel Deposition - Ni catalyzed graphene formation (J.-C. Ye).— Electroless Au deposition (S.H. Kim).TemplatingDouble Tubular 3D Graphene Foam5 µmAM PolymerRemovalTa2O5 Hollow Tubes5 µm16LLNL-PRES-xxxxxx

Questions In Summary:— We have shown that additively manufactured foams prepared through direct laserwriting via two photon polymerization, can be directly integrated (i.e. without tooling)into experimental HED target packages in place of traditional aerogel materials.— An interdigitated NanostitchTM strategy was developed to mitigate stitching induceddefects thereby improving density-homogeneity and mechanical stability.— The complexity freedom of additive manufacturing opens the door for more complexarchitectures, such as a graded densities and functional hohlraum liners.17LLNL-PRES-xxxxxx

HED Physics Target Fabrication by Additive Manufacturing Target Fabrication Meeting 2017 Presenter: James Oakdale March 12-16, 2017. LLNL-PRES-xxxxxx 2 Accelerated Development of Multiscale Ma