1. HAPL-14: S. Sharafat 1/25 Ion Implantation in SiC: 365 MJ Target Spectra 14 th High Average Power Laser Program Workshop Oak Ridge National Laboratory Oak Ridge, TN March 21-22, 2006 S. Sharafat, M. Andersen, Hu Qiyang, and N. Ghoniem University of California Los Angeles Glenn Romanoski Oak Ridge National Laboratory

2. HAPL-14: S. Sharafat 2/25 OUTLINE Ion Implantation Issues (9 slides) Possible New Concepts for SiC/SiC (3 slides) Supportive Activities: (2 slides)

3. HAPL-14: S. Sharafat 3/25 R. Raffray, HAPL March 2006

4. HAPL-14: S. Sharafat 4/25 Implantation Calculation For each Ion: –Run SRIM at every energy –Add all profiles ( % weighted ) SiC

5. HAPL-14: S. Sharafat 5/25 Ion Implantation in SiC Sample Implantation Profiles using Perkin’s 365 MJ Target Spectra (SRIM2003) Profiles for all ions, 1H, 2H, 3H, 3He, 4He, 12C, 13C, Au, Pd were developed Implantation Profile for 1 HImplantation Profile for 12 C Range

6. HAPL-14: S. Sharafat 6/25 Ion appm (atomic parts per million) Profile in SiC Per Shot 13 C 12 C 13 C 12 C

7. HAPL-14: S. Sharafat 7/25 Fraction of Ions at Mid-Bin Energy

8. HAPL-14: S. Sharafat 8/25 Ion Damage in SiC per Shot Ion Damage Profile (SRIM2003) for: 1H, 2H, 3H, 3He, 4He, 12C, 13C, Au, Pd Vacancy Generation Profile for 4 HeVacancy Generation Profile for 12 C

9. HAPL-14: S. Sharafat 9/25 Ion Damage in SiC per Shot

10. HAPL-14: S. Sharafat 10/25 Carbon Implantation and Formation of WC Carbon Concentration Profile Evolution in W 13 th HAPL Meeting

11. HAPL-14: S. Sharafat 11/25 Formation of WC At 2000 o C solubility of C in Tungsten is of the order of 0.05 at. % Solubility of C in W: UCLA FusionNETWORK fusionNET.seas.ucla.edu WC forms between 1150 and 1575 K W 2 C forms between 1575 and 1660 K D. Gupta, Met.Trans. A 1975  Carbon reacts with Tungsten to form WC and W 2 C inside the W-armor  Complex model: (1) Chemical reaction; (2) Diffusion; (3)T-swings; (4) T-gradients.  Need for Experiments on WC: Effect of H and He implantation on - Mechanical Properties of WC - Helium and Hydrogen Release  Discussions with ORNL(G. Romanoski ) have identified testing facilities (G. Romanoski )

12. HAPL-14: S. Sharafat 12/25 Carbon Implantation in SiC Implantation of 12 C per shot: Carbon Implantation range: 1.75  m For 10.1 m chamber implantation range has ~1x10 26 SiC Number of C per shot: ~6.8x10 19 C/shot:  After 1x10 6 shots (~1.2 days) C/SiC ratio approaches unity (or SiC 2 ) assuming no diffusion Concerns Regarding Excess Carbon in SiC: Carbon diffuses readily (int. + substit./detrapping) Carbon can bond chemically with H, D, and T Formation of Hydro-carbons C x H y  T retention?  Chemical Trapping of H, D, T slows down proton diffusion, defect annealing, and may interact synergistically with He  Pursuing rate of Hydro-Carbon formation [Huanchen, Ghoniem 1994]

13. HAPL-14: S. Sharafat 13/25 Hydrogen Implantation in SiC Implantation of H, D, T : SEM micrograph image of blisters formed in the 6H-SiC irradiated at 300 K (1.0x10 17 H + /cm 2 ) and then annealed at 1070 K for 20 min. [Jiang, NIMB2000] HAPL:365 MJ Target 10.1 m Chamber ~ 1x10 16 H/m 2  Roughening of SiC (HAPL conditions?)  Effect of Chemical Trapping of H, D, T on roughening?  Experiments: H + -+ He beam (HAPL conditions)? Taguchi, JNM2004: Synergistic effect of H, He, +Si implantation: Only He-implantation  no bubbles at 1300 o C (T impl ) Dual/Tripple (He, H, Si)  Helium bubbles formed at GB

14. HAPL-14: S. Sharafat 14/25 Possible New Concepts for SiC Armor Nanopillars and Dendrites Ion-Barrier Coating (IBC) Flexible Armor w/o Transpiration Cooling

15. HAPL-14: S. Sharafat 15/25 Possible New Concepts for SiC Armor: Nanopillar Helium Implantation in CVD SiC: 26.3 MeV with 51 degrader foils shows DENUDED ZONE ~0.5  m near Grain Boundary [Poster by Hu Qyiang]  Nanopillars: [Chen, Jung, Trinkaus, PRB 2000] {

16. HAPL-14: S. Sharafat 16/25 Possible New Concepts for SiC Armor: Nanopillars & Dendrites Surface textures that were achieved in black W coatings applied to W [Ultramet 2005] High emissivity CVD dendritic Re coatings applied to solid CVD Re surfaces [Ultramet,2005] Dendrites“Cauliflower” Concept is based on: Make use of characteristic diffusion length of helium (Denuded Zones in SiC ~0.5 um) Choose materials which have <1 um size features: dendrites, pillars, cauliflower

17. HAPL-14: S. Sharafat 17/25 Possible New Concepts for SiC Armor: IBC Coating The UEET (Ultra Efficient Engine Technology; NASA) is developing SiC/SiC composites with EBC (EBC: Environmental Barrier Coatings) EBC have low thermal k  Ion-Barrier Coating (IBC) SiC Armor: Doug Freitag 301.570.3821 dfreitag@ix.netcom.com 4 April 2002 dfreitag@ix.netcom.com New EBC with no degradation: 300h, 1400 o C (2552 F) 1h cycles, 90 H 2 O-bal O 2 { Melt- Infiltrated SiC/SiC  Glass-forming materials have a relatively open crystal structure, which enhances ion release and self-healing.  Is there a combination of high thermal conductivity materials that could be combined with glass forming materials. (Si 3 Ni 4 - MoSi 2, Si 3 N 4 -SiC, SiO x N y B z ) that will allow for high release of implanted ions ?

18. HAPL-14: S. Sharafat 18/25 Possible New Concepts for SiC Armor: Flexible w/o Transpiration Cooling Use a Flexible Fibers oNo matrix material oFibers should be ~few microns in diameter to enhance Ion-release oKeep armor flexible to accommodate loads  Flexibel SiC-Fiber 2/3-D Weave Armor with Transpiration Cooling: Sylramic™ SiC Fiber 2-D Weave Concern: Thermal conduction path of the weave to underlying structure. Wetted-Solid  Evaporative Cooling Wick sufficient liquid to serve as a sacrificial layer to take care of all ions Use structure (W-fibers, dendrites, nanopillars, nano-grains) to hold liquid and to conduct heat

19. HAPL-14: S. Sharafat 19/25 OUTLINE Ion Implantation Issues (9 slides) Possible New Concepts for SiC/SiC (3 slides) Supportive Activities: (2 slides)

20. HAPL-14: S. Sharafat 20/25 FusionNET™ Database: Update A new category has been added to FusionNET™: ─ ITER Materials Handbook All ITER Tungsten Properties are available: · Density · Electrical Resistivity · Emissivity · Enthalpy · Fatigue S-N Curve · Poisson's Ratio · Reduction in Area · Specific Heat · Tensile Strength · Thermal Conductivity · Thermal Expansion · Total Elongation · Uniform Elongation · Vapor Pressure · Yield Strength · Young's Modulus· Density · Electrical Resistivity · Emissivity · Enthalpy · Fatigue S-N Curve · Poisson's Ratio · Reduction in Area · Specific Heat · Tensile Strength · Thermal Conductivity · Thermal Expansion · Total Elongation · Uniform Elongation · Vapor Pressure · Yield Strength · Young's Modulus ITER Li, Be, ClidCop, 316 (LN)IG being uploaded

21. HAPL-14: S. Sharafat 21/25 HiCAT- A Novel In-situ Mass Loss Diagnostic Tool  A compact (~15 mm diam.), high power hollow pulsed cathode discharge has been developed to ionize vaporized/ablated chamber wall material.  Quantitative spectroscopy is used to determine : ─ Species Composition, and ─ Density of ablated/vaporized material  High sensitivity, high time resolution detection (< 100 ns)  Operation in Argon background gas (0.01-10 torr) or as vacuum arc  Studied Chamber clearing in Z-Pinch L. Schmitz, P. Calderoni, Y. Tashima, A. Ying (MAE-UCLA) Schematic of HiCAT device Measured Lithium density compared to vapor pressure equilibrium density (p Ar = 0.3 torr) L. Schmitz et al., J Nucl. Mat. 337-339 (2005) 1096 ~1.5 cm

22. HAPL-14: S. Sharafat 22/25 Summary and Conclusions Ion Implantation: “Busy” implantation region (~10-20  m in SiC; < 5  m in W) Synergy of implanted H and He (He-trapping, SiC, W) Chemical interaction of excess carbon with H, D, T (SiC, W) WC formation is favored because of low solubility and large negative Gibbs Free Energy of Formation Roughening of SiC due to low energy H implantation Concepts: Nanopillars/Dendrites: < 1um to enhance ion release from SiC IBC: Ion-Barrier Coating with glass formers to enhance ion release Flexible (fiber) w/o Transpiration cooling Supportive Activities: FusionNET™: ITER MPH Tungsten have been added to FusionNET™ Mass Loss Analyzer: In-situ mass-loss analyzer (scan rate >100 ns).

23. HAPL-14: S. Sharafat 23/25 Background Slides

24. HAPL-14: S. Sharafat 24/25 Ion Implantation Profile in SiC per Shot 12 C

25. HAPL-14: S. Sharafat 25/25 From J. Perkin’s HAPL 365 MJ Target

26. HAPL-14: S. Sharafat 26/25 HiCAT Pulsed High Power Operation Ar Ion Lines High density, nearly fully ionized plasma (n < 10 17 cm -3, kT e < 2 eV) with local thermodynamic equilibrium (LTE) allows simplified spectroscopic determination of plasma parameters needed to interpret materials spectra. A Rapid sequence of pulses allows high time resolution (< 100 ns) analysis of mass loss, ablated/vaporized material density, and species composition. Works in Argon background or as vacuum arc. Ar Neutral Lines Z-BoxTest Chamber (Vacuum Capable Glove Box) Lens Fiber Optic Capacitor Bank 2 kJ Dual 0.27 m Monochromators Ocean Optics compact spectrometer PMT

27. HAPL-14: S. Sharafat 27/25 HiCAT Diagnostics (Continuous operation) End-on View of HC Discharge in Argon Schematic showing spectroscopy and Langmuir probe set-up Plasma Parameters obtained from Probe data Ar Ion lines Ar neutral lines Low current, low plasma density; minimally invasive diagnostics; highest trace detection sensitivity under equilibrium conditions. Required back- ground pressure 0.01-10 torr Argon Emission Spectrum

28. HAPL-14: S. Sharafat 28/25 Density Profiles (SRIM) DEBRIS-IONS 12 th HAPL Meeting

29. HAPL-14: S. Sharafat 29/25 High T implantation: ~2x10 17 T/m 2 per shot for a R=10.1 m chamber. Effects of Carbon on T retention at High Temperatures? Impact of Carbon Implantation: Tritium Retention Irradiated tungsten at 653K with carbon concentration as a parameter (1 keV ~7× 10 24 H/m 2 [Ueda,2004].

30. HAPL-14: S. Sharafat 30/25 Self-Damage (Defect) Rate Profiles (SRIM)