1. 1 Progress in the field of first mirrors A. Litnovsky for the First Mirror SWG

2. 2 First mirror activity in the Russian Federation Compiled by K. Vukolov A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

3. 3 FM activity in RF: 1. Choice of material and type of mirrors 2. Development of technologies for fabrication of high quality mirrors Mirrors with Rhodium nanocrystalline coating - N.V. Klassen, this meeting Mo mirrors with nanocrystalline column coatings – A.V. Rogov, this meeting Multilayered dielectric mirrors – I.I. Orlovsky, this meeting Large SC Mo mirrors – EU contract Finishing polishing by ion etching – EU contract 3. Study of mirror properties Laser test of Mo and Cu mirrors – V.V. Sannikov, this meeting Sputtering, blistering 4. Deposition and cleaning Research on mirror cleaning in low temperature plasmas – G.T. Razdobarin, this meeting Heating effect on deposition of H:C films and reflectivity of metallic mirrors – K.Yu. Vukolov, this meeting A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

4. 4 I)Table of main results ActivityResult Large SC Mo mirrors (“Luch”, Podolsk, RF) Mo single crystals of  120-140 mm Mirrors with Rh coating (IPP, Chernogolovka) Mirrors with Mo coating (Kurchatov) Plasma and ion treatment (Kurchatov) Samples stable under sputtering Mo mirrors stable under sputtering Finishing polishing of metallic mirrors Thermal and Neutron Tests of Multilayered Dielectric Mirrors (Kurchatov) The mirrors resisted to neutrons up to 10 19 n/cm 2 and 250  C heating High power YAG-laser test of Mo and Cu mirrors (Kurchatov) Durability of the mirrors under pulsed laser radiation Research on mirror cleaning in RF discharge (Ioffe) Heating effect on deposition of H:C films (Kurchatov) Potential tools for cleaning of in-vessel diagnostic mirrors A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

5. Institut für Plasmaphysik EURATOM Assoziation – FZJ TEC Forschungszentrum Jülich in der Helmholtz-Gemeinschaft 5 Investigations at IPP Forschungszentrum Jülich A. Litnovsky for A. Kirschner, A. Kreter, S. Droste, V. Philipps, P. Wienhold, D. Borodin and TEXTOR Team. A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

6. Institut für Plasmaphysik EURATOM Assoziation – FZJ TEC Forschungszentrum Jülich in der Helmholtz-Gemeinschaft 6 interaction layer bulk volume (tungsten) e.g.: net-erosion c W (t) c C (t) C, W plasma “Simple mixing surface model” “Surface model of TRIDYN” plasma layer 1 layer 2 layer N e.g.: net-erosion c W,1 (t) c C,1 (t) C, W c W,2 (t) c C,2 (t) c W,N (t) c C,N (t) Erosion and deposition: surface models

7. Institut für Plasmaphysik EURATOM Assoziation – FZJ TEC Forschungszentrum Jülich in der Helmholtz-Gemeinschaft 7 50100150200 0 0.02 0.04 0.06 0.08 Electron temperature [eV] C sputtering yield 8A 20A 80A pure carbon layer thickness d “simple mixing model”  multi-layer model necessary for thin layers high impact energies Necessity of a multi-layer surface model: TRIDYN Influence of substrate material on the deposition efficiency A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

8. Institut für Plasmaphysik EURATOM Assoziation – FZJ TEC Forschungszentrum Jülich in der Helmholtz-Gemeinschaft 8 graphite tungsten 4 % Local deposition efficiency: 0.3 % Experimental observations: 13 C deposition efficiency from injected 13 CH 4 in TEXTOR Influence of substrate material on the deposition efficiency A. Kreter et al, Proc. of 32nd EPS Conference on Plasma Phys. ECA Vol.29C, P-1.014 (2005) A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

9. Institut für Plasmaphysik EURATOM Assoziation – FZJ TEC Forschungszentrum Jülich in der Helmholtz-Gemeinschaft 9 “TRIDYN surface model“ vs. “simple mixing model”: ► decreased local deposition efficiencies ► stronger substrate dependence TRIDYN surface model is closer to the observations from the experiment Locall deposition efficiency 13 C experiment ERO modeling with: TRIDYN surface model Simple mixing model C4%2.8%7.2% W0.3%0.9%6.3% Comparison of modeling with experimental results. Influence of substrate material on the deposition efficiency Modeling: ERO code coupled with TriDyn A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

10. Institut für Plasmaphysik EURATOM Assoziation – FZJ TEC Forschungszentrum Jülich in der Helmholtz-Gemeinschaft 10 New Experiment with Striped C/Mo/W limiter Aim: Further Benchmark of the coupled ERO – TRIDYN code Picture: Harry Reimer toroidal direction erosion - zone deposition - zone Carbon Molybdenum Tungsten Influence of substrate material on the deposition efficiency Courtesy S. Droste Ideas: ● Observe carbon background deposition on different materials for the direct comparison; ● Use reproducible discharges; ● Expose the materials under the same plasma conditions. A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006 Surface analysis is underway

11. Institut für Plasmaphysik EURATOM Assoziation – FZJ TEC Forschungszentrum Jülich in der Helmholtz-Gemeinschaft 11 Investigations of first mirrors: Current activities ► Direct comparative test of single crystal (SC) and polycrystalline Mo and W mirrors under erosion conditions: investigations are finished; ► Mirror tests in DIII-D divertor: mitigation of deposition. Deposit quantification with SIMS: done; NRA measurements of C and D on the mirrors; Modeling (collaboration with Jeff Brooks, ANL). Left Right 4 nm (C) Down 26.4 nm (C) ~ 91.5 nm (O)* 105.6 nm (C) 47.8 nm (C) On the photo: Deposit thickness distribution on the mirror exposed in DIII-D divertor Results of calibrated SIMS measurements A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

12. Institut für Plasmaphysik EURATOM Assoziation – FZJ TEC Forschungszentrum Jülich in der Helmholtz-Gemeinschaft 12 Future plans: 2006 A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006 Tests of ITER candidate mirror materials and technologies; ► Direct comparative test of SC Mo and Mo mirror with nano-coating in controlled erosion conditions in the SOL of TEXTOR (collaboration with KI and Univ. of Basel); ► Direct comparative test of SC Mo, Rh-coated and amorphous mirrors under erosion conditions in the SOL of TEXTOR (collaboration with KI and Univ. of Basel); ► Large Mo mirrors for ITER diagnostics (EFDA EU-RF contract) Carbon transport and the mitigation of deposition on mirrors in a diagnostic duct: ► Experiment with Periscope-Upgrade system. Joint experiments: ► New exposure of mirrors in the DIII-D divertor (details later in this presentation); ► Mirror experiments in the divertor and pump-duct of ASDEX-Upgrade: presently being discussed.

13. 13 Investigations performed in the University of Basel and in TCV Tokamak Compiled by G. De Temmerman A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

14. 14 Exposure of mirrors in TCV Mirrors located in the divertor region and recessed below the surface of divertor tiles, no direct contact with the plasma.  Simulation of mirrors placed in diagnostic duct; No shutter installed at moment but the sample manipulator is electrically insulated from the torus; Tests of different candidate materials by pair. Sample exposures were integrated over short campaign periods of 2-3 weeks, including He glow discharge conditioning A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

15. 15 Substrate effect Test of different materials and different recessment distances Strong differences in the thickness measured on Si and Mo samples under similar exposure conditions Thickness determined by ellipsometry/SIMS/ profilometry Deposited layer consists mainly of carbon and deuterium A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006 ExperimentMaterial Distance below the tile surface (mm) Number of shots Glow discharge (hrs) Deposited thickness (nm) Mo 1.3 Si 15.89 Mo 4 Si 24 4 5 50 223 24.5 820 90.5

16. 16 Mirror research at DIII-D: status overview D.Rudakov, A. Litnovsky, S.L. Allen, J.A. Boedo, R.L. Boivin, N.H. Brooks, M.E. Fenstermacher, M. Groth, C.J. Lasnier, A.G. McLean, R.E. Moyer, V. Philipps, P.C. Stangeby, G. De Temmerman, W.R. Wampler, J.G. Watkins, W.P. West, P. Wienhold, C.P.C. Wong. A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

17. 17  A new divertor shelf has been installed;  Divertor diagnostics had to be adjusted for the new divertor level;  DiMES mechanism was modified;  New: capability to expose material samples using the mid-plane reciprocating probe drive. New shelf DiMES MiMES MiMES = Mid-plane Material Evaluation System A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006 Modified lower divertor in DIII-D DiMES and MiMES

18. 18 New mirror experiments in DIII-D ● To repeat the heated experiment at fixed elevated temperature(150 o C) using the existing DiMES Mirror holder; ● If more machine time available, repeat the non- heated experiment to study the reproducibility in the new divertor. DiMES Mirror Sample PFR 150 o C Aims: The possibility to test other mitigation techniques ROF Proposal A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

19. 19 Modeling: joint activities of ORNL (USA) and CEA Cadarache (EU) Compiled by J. Hogan A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

20. 20 Validation tests for ITER mirror deposition model J Hogan *, E Dufour +, P Monier-Garbet +, C Lowry +, E Tsitrone +, R Mitteau +, * Fusion Energy Division ORNL, + DRFC, CEA-Cadarache ● Deposition on ITER diagnostic mirror depends on the initial rate of generation, transport in the SOL to the mirror and, finally, the local mirror deposition rate; ● A validated quantitative model for the initial generation rate is so far lacking; ● To develop this, the BBQ code is applied to model the complex TS CIEL environment, comparing with local measurements of CII / D a emission from zones in deposition and shadowed regions; ● Results - high T e regime (physical and self-sputter processes) reasonably well modeled; - low T e regime: chemical erosion (J.Roth et al. J. Nucl. Mater 337-339, p.970, 2005) shows low values, but inclusion of sources from intra-tile gaps leads to improved agreement; A collaboration has started to use ERO code (A.Kirschner (IPP FZJ) et al. to model intra-gap processes. A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

21. 21 - Physical, self-sputtering values in range (more work to do on self-sputtering) - Chemical sputtering (D+ flux suppression model*) is too low, Inclusion of measured higher temperatures in intra-tile (gap) region raises Y chem BBQ validation: comparison * J Roth et al.,J Nucl Mater, 337-339, p.970, 2005 BBQ calculation of CD 4 emission, using IR data for T surf A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006 10 10 10 Sputter yield -3 -2 -1 Y phys (Voie 3) Y self Z=6 (Voie 3) 1020304050 T e (a) eV Y self (Zone 3) Y phys (Zone 3) Y phys (Zone 3) Y chem (Zone 3) without tile gap effects) Y chem (Zone 3) cases including tile gap effects

22. 22 Mirror Research at ANL (USA) Compiled by J. Brooks and J. P. Allain A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006

23. 23 Status/plans for ITER diagnostic mirror research J.N. Brooks, J.P. Allain, A. Hassanein, M. Nieto Argonne National Laboratory 10 th ITPA TG on Diagnostics, Moscow April 10-14, 2006

24. 24 Erosion/Deposition of ITER diagnostic mirrors: Plans for Code/modeling & Experiments* We can compute the particle and energy fluxes to the mirrors, and erosion/deposition, as an add-on to planned work on ITER plasma facing component plasma/surface interaction. Key resources: Code Package OMEGA (edge/sol plasma, sputtering, impurity transport with LLNL), HEIGHTS Code Package (transient response). We are developing the MC-Mirror code: Monte-Carlo D-T, He, Be transport from plasma, through ducts, to mirrors. Includes sputtering and reflection of/from duct boundaries. Includes helium neutral generation in edge plasma (via charge exchange of He particles reflected from the wall), transport to mirrors Inputs/Connection to MC-Mirror code from Package-OMEGA.) (with University of Wisconsin) We can compute (via IMD code) the effect on mirror performance. We can study experimentally, via ANL/PRIME facility, the effects of particles/heat on ITER candidate mirrors. * Subject to funding.

25. 25 ANL Preliminary Tasks: IMD code IMD ( D.L. Windt, Comp Phys 12 (1998) 360) is a computational program that models the optical properties including: reflectance, transmittance, phase shifts and electric-field intensities of multi-layer films and multi-component surfaces; IMD will be linked with particle-induced damage surface codes; Preliminary scoping tests of a Au-coated (1.0 µm) mirror with various Be coating thicknesses using the IMD computational code;

26. 26 We couple our modeling capabilities with in-house experimental measurements The Particle and Radiation Interaction with Matter Experiments (PRIME) facility includes: –State-of-the art in-situ surface metrology (IMPACT experiment) that monitors the behavior of surfaces at various depth scales under high- flux ion irradiation; –Several ion sources with fluxes 10 11 -10 16 ions/(cm 2 *sec), 25-500 C, impact angles 0-65 degrees, 5-5000 eV; –Species: H, D, He, C, N, O, Ne, Ar, Kr, Xe, and Sn; others: C 60, Au n –A full-scale, high-power laser system custom designed and tunable between 193-nm and 2200-nm; –Up to three ion sources can be run simultaneously. Experience: We have studied extensively the role of energetic ions on plasma-facing mirror performance used in EUV lithography; This expertise can be leveraged to further understand the role of particles on first mirrors in ITER and to develop schemes of their protection.

27. 27 Example: Sn exposure results on grazing incidence Rh mirrors for EUV lithography Sn is studied since it is primary EUV radiator candidate for EUV lithography; Experiments at Argonne measure time-dependent erosion rates, Sn implantation and deposition and in-situ EUV reflectivity; Figure shows surface Sn fraction as Sn vapor is deposited on Rh mirror with about 20% loss of reflectivity at 13.5 nm and 15-degree grazing incidence.

28. 28 Summary A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006 ● Significant progress is achieved in the R&D of mirrors for erosion environment; ● Intensive research is ongoing in the field of mirror cleaning techniques; ● The mitigation of the deposition at elevated temperatures is proven to be a complex process, depending on exposure conditions; ● The choice of the substrate (mirror) material strongly influences the deposition efficiency. This needs to be investigated in future in more details; ● Good potential and interest in modeling of mirror performance in ITER, made and planned experiments; ● Closer collaboration with PWI community on issues of common interest.

29. 29 Thank you A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006