1. Gottfried Besenbruch, Lloyd Brown, Tom Drake, Peter Ebey, Jim Hoffer, Haibo Huang, Barry McQuillan, Farrokh Najmabadi, Abbas Nikroo, Art Nobile, Ron Petzoldt, Rene Raffray, Diana Schroen, Bob Stemke, Jon Streit, Masa Takagi, Mark Tillack, Brian Vermillion, Tracy Woo Presented by Dan Goodin Update on IFE Target Fabrication High Average Power Laser Program Workshop Naval Research Laboratory Washington, DC December 5-6, 2002

2. Target Fabrication Topics 1) Target Fabrication and Injection Plan for Next 3 Years - Ron Petzoldt - Target Injection Status - Rene Raffray - Target Survival Modeling 2) “Building 22” Status (GA’s IFE Development Facility) 3) Microencapsulation Scaleup Studies 4) Status of Target Costing Evaluations 5) Fluidized Bed for IFE Target Fabrication (OFES Grant) talks this afternoon survival workshop tomorrow afternoon

3. Target Fabrication Phase I Goals 1.Develop mass production methods to fabricate cryogenic DT targets that meet the requirements of the target design codes and chamber design. Includes characterization. 2.Combine these methods with established mass production costing models to show targets cost will be less than $0.25. Developed thin Au/Pd coatings with high DT permeability and IR reflectivity. Established chemistry for foam shells General Atomics Schafer Corp Targets $0.16 each from chemical process plant methodology General Atomics

4. Target Injection / Tracking Phase I Goals 1.Build an injector that accelerates targets to a velocity to transverse the chamber (6.5 m) in 16 milliseconds or less. 2.Demonstrate target tracking with sufficient accuracy for a power plant (+/- 20 microns). Turbo Pumps Gun Barrel Target Catcher Target Position Detectors Sabot Deflector Revolver Chamber Expansion Tanks 1.Started Construction of Gas Driven Target Injector 2.Demonstrated Concept of Separable Sabot 3.Determining needed properties of DT General Atomics, LANL

5. Structure of “Target Plan” Make Foam Shells Add Seal Coat Add High-Z Coat Filling Layering Injection and tracking Survive Injection Main Process Steps Characterize 1. Produce foam shells 2. Make seal coat 3. Provide high-Z coat 4. Eval surface in a torus 5. Demo mass-prod layering 7. Demo target injection 8. Meas DT response 9. Model target/chamber interface Adapt shell manufacture to mass production 6. Process development Develop mass-prod methods Initial plant layouts and equipment Show economical target supply Schafer Corp General Atomics LANL GA/UCSD Integrated Self-Consistent Target Supply Scenario

6. Year 1| Year 2|Year 3| Target Fab/Injection 3-Year Deliverables (FY03-FY05) Produce initial foam shells/seal coat/high-Z Capsules Eval scaleup methods Prod shells w/mass-prod methods Layering Eval foam effect Design and build mass-production layering equip Demo mass-prod layering Heat flux on filled target Injection Upgrade to rep-ratedConduct parametric expsDemo hit-on-fly Integrated survival model Process Development Initial layouts & equipUpdate with R&D dataShow economical targets Integrated Self-Consistent Target Supply Scenario Meas heat flux effectMeas DT strength

7. Target Fabrication/Injection Tasks 1) Foam shell production (Schafer) FY03 - Produce, using R&D scale equipment, target quality foam shells meeting requirements for the high gain direct drive target. Provide polymer seal coat on foam shells meeting requirements for the high gain direct drive target. 2) Foam shell overcoat (Schafer) FY03 - Provide polymer seal coat on foam shells meeting requirements for the high gain direct drive target. FY04 - Adapt shell making and seal coat processes to mass production; interface with process design studies to show a feasible and economical mass-production pathway. 3) Application of high-Z layer (GA) FY03 - Optimize high-Z over coat for high gain direct drive target target, accounting for target design, permeability, and reflectivity considerations; demonstrate techniques amenable to mass production. Schafer Corp 600 Å Pd on PAMS shell

8. Target Fabrication/Injection Tasks 4) Cryo layering #1 (LANL) FY03 - Measure the surface finish of a DT layer formed in a torus with a foam underlay (to determine the smoothing effect of the foam). 5) Cryo layering #2 (GA) FY03 - Complete a detailed design and initiate procurement of a lab-scale system to demonstrate layering of direct drive targets by mechanical motion production (e.g., fluidized bed, bounce pan, and/or spiral tube). FY04 - Complete procurement and install equipment to demonstrate cryogenic layering of hydrogen isotopes on lab-scale. FY05 - Conduct shakedown and operate lab-scale system to demonstrate mass-production layering method. Surrogate layering demo with neopentyl alcohol LANL torus

9. Target Fabrication/Injection Tasks 6) Process development and costing (GA) FY03 - Provide initial definition and layouts equipment for fabrication of direct drive targets. Operate microencapsulation equipment to evaluate scaleup methods and provide shells for other experiments FY04 - Incorporate continuing target program R&D data into the Target Fabrication Facility (TFF) equipment lists and plant layouts. Operate microencapsulation equipment to parametrically evaluate methods for scale-up. FY05 - Support the IRE decision process by providing a chemical engineering approach to the TFF and the IRE pilot-plant target factory that is integrated with results from experimental programs. Fabricate foam shells and seal coats using mass-production methods H 2 O/ PVA DVB with initiator Example process equipment

10. Target Fabrication/Injection Tasks 7) Target injector (GA) FY03 - Procure components and convert system to rep-rated operation (6 Hz for 12 shots). FY04 - Complete shakedown of injection and tracking system (gas-gun) in rep-rated mode; refine and optimize tracking system as needed. FY05 - Complete injection and tracking studies of parametric conditions (velocity, acceleration, gas pressure, etc.) to demonstrate design windows for meeting tracking accuracy requirements of  20  m. Install a surrogate final optics/mirror unit on injection/tracking system and interface to tracking commands to provide an integrated demonstration of high-speed tracking and hitting the target on-the- fly with a low-power laser (with UCSD collaboration). Injection system components

11. Target Fabrication/Injection Tasks 8) DT response during injection (LANL) FY03 - Deposit a layer of DT in a torus and observe effect of rapid heat pulse FY04 - Conduct experiments to determine the ability of DT with foam underlay to survive rapid heat pulse. Measure elastic modulus and yield strength of DT under representative strain rates, repeat with foam-reinforced DT. FY05 - Measure DT response with rapid IR heating of filled spherical targets. Foam-lined torus cutaway view, LANL

12. Target Fabrication/Injection Tasks 9) Target/chamber interface (GA/UCSD) FY03 - Perform assessment of cryogenic materials properties necessary for target/chamber interface modeling. Develop modeling capabilities. Perform trajectory analysis in coordination with injection tasks. FY04 - Conduct parametric analyses of target response during cryogenic handling and injection; provide feedback to guide R&D. FY05 - Bring together materials property data, models of target response during injection, and experimental program results to show a workable solution for direct drive target injection.

13. We’ve moved into the “Building 22” complex  Additional 7200 SF lab space  And 6900 SF of office space  GA’s “IFE Development Facility” Future chem labs 22-T Offices B22 Lab

14. Capsule fabrication by microencapsulation Basic schematic of microencapsulation  Microencapsulation is the planned method for making IFE shells  Schafer now developing methodologies for DVB foam  GA is interested in scaling this for mass-production Finished Cryogenic Target (4.0  0.2 mm OD) DT Gas Solid layered DT at ~18K DT-filled DVB foam shell - CH polymer - 20-120 mg/cc (  20%) - 290  20  m - 1 to 3  m cell sizes - OOR: 1% of radius - NC: 1% of wall - density to  0.3% 50-100  m Overcoat (seal) - 1 to 5  m - 1.4  0.2 g/cc - 50 nm RMS High-Z coating - 30-100 nm thick - 50 nm RMS - Au/Pd mixtures

15. We have begun experimental studies for mass- production microencapsulation  Our goal is to show microencapsulation is an efficient and cost-effective method  Yield, reproducibility, optimization for cost, etc.  Setup equipment to (a) produce shells for other studies, and (b) to experimentally evaluate mass- production techniques We started with PS shells (unfiltered solutions) Photo of some shells made at GA - Brian High-speed video for droplet formation

16. Development is focused on enhancing yield and reliability for mass-production  We have in mind 3 initial modifications  Adding a pulser to better control drop formation  Replacing handmade glass needles with machined steel  Providing a “scaleable” contactor for processing  Changing the contactor size changes process  Re-optimize as we make the contactor larger  Need alternative contactor design to avoid this scaleup issue Laboratory scale contactor ~16 cm ~4’ Potential production-scale Sol-gel fuel production Machined needle design

17. Alternative contactor design - a “gas sparger”  Bubbler with frit to allow gentle agitation  Once chamber is large enough to avoid wall effects, then size shouldn’t matter Gas sparger concept Water bath to control temperature

18. First experiments done  Parametric study comparing to rotary contactor  Same shells into rotary system and into gas system  Shells into 3% PVA/H 2 O and into DI H 2 O Dropping with glass needle so far Experimental system components Assembled unit

19. View of bubbles/shells Bubble to shell size ratio of about 65%

20. IFE target costing studies are being published … Basic conclusion is that the NRL direct- drive high-gain target can be mass-produced for about $0.16 each 1) “Cost Modeling for Fabrication of IFE Targets”, Rickman and Goodin, accepted for publication in Fusion Science and Technology, printing May 2003.  Direct drive target production 2) “The Viability of an Economical Target Supply for Inertial Fusion Energy”, D.T. Goodin, A. Nobile, D. G. Schroen, G.E. Besenbruch, L.C. Brown, J.L. Maxwell, W.R. Meier, T. Norimatsu, R.W. Petzoldt, W.S. Rickman, W. Steckle, J.P. Dahlburg, 1 and E.M. Campbell  Planned submittal to Nuclear Fusion ~January, 2003  Covering both direct and indirect drive targets 3) “GA-C” type report with details of modeling, appendices, etc.  Controlled distribution available upon request  Contains the detailed basis for direct and indirect drive target modeling

21. Fluidized bed GDP coating results  Method is potentially applicable to both indirect and direct drive targets  To make high concentricity thick-walled shells for HIF  To add “CH-only” overcoat to “smooth” DVB foam shells  Basic concept is to scaleup bounce pan method of coating GDP onto PAMS mandrels  Previous work coated ~ 3  m thick  Issues with coating rate, frit and particulates, and “arcing”  Recent accomplishments  Fluidized without frit (cone)  Deposited arcing-free with good rate  Obtained thick coatings  1.2  m/h  High-quality coatings  Maximum 147  m coating

22. 16.8  m GDP on 2000  m diameter PAMS shell with 35  m wall Transparent & brownish coloredModerate surface roughness Made relatively smooth, transparent coatings

23. AFM spectrum of 16.8  m GDP from fluidized bed Wyco shows about 28 nm surface roughness

24. Target fabrication summary … The IFE target development issues have been identified and are being addressed by the ongoing work  A “Target Plan” to address direct drive target fabrication and injection issues has been jointly drafted by GA, LANL, Schafer, and UCSD  Microencapsulation equipment  Setup and shaken down system  Making PS shells for testing purposes  Scaleup studies underway with testing of mass-production methods  Target Fabrication Facility (TFF) scaleup studies and costing models are being published/documented  Coating in a fluidized bed has shown potential for high-quality coatings and for higher coating rate operations