1. © Olga Ogorodnikova, 2008, Salamanka, Spain Current status of assessment of Tritium inventory in all-W device O.V. Ogorodnikova and E. d’Agata

2. © Olga Ogorodnikova, 2008, Salamanka, Spain Be: port limiter, primary wall, baffle W: upper vertical targets, dome CFC: lower vertical targets Initial plasma-facing materials for ITER divertor

3. © Olga Ogorodnikova, 2008, Salamanka, Spain Tungsten ITER divertor Upper part Inner VT Upper part Outer VT Dome Act as baffles for the neutrals 100 m 2

4. © Olga Ogorodnikova, 2008, Salamanka, Spain CFC ITER divertor Lower part Inner VT Outer VT Lower part Outer VT Interact directly with the scrape-off layer plasma 50 m 2

5. © Olga Ogorodnikova, 2008, Salamanka, Spain W ITER divertor Lower part Inner VT Outer VT Lower part Outer VT Interact directly with the scrape-off layer plasma 50 m 2

6. © Olga Ogorodnikova, 2008, Salamanka, Spain Vertical Target W monoblocks (upper and bottom half) Mario Merola and ITER team

7. © Olga Ogorodnikova, 2008, Salamanka, Spain Dome W flat tiles with HV cooling Mario Merola and ITER team - flat tile concept cooled by HV-

8. © Olga Ogorodnikova, 2008, Salamanka, Spain First Wall W CuCrZr Mario Merola and ITER team W macrobrush: W/CuCrZr Plasma spray W: PSW/CuCrZr

9. © Olga Ogorodnikova, 2008, Salamanka, Spain Tritium inventory Joachim Roth: PSI-18 Toledo, May 26, 2008

10. © Olga Ogorodnikova, 2008, Salamanka, Spain Talk outline - T retention in outer vertical target - T retention in inner vertical target - T retention in dome - T retention in FW Normal operation regime Comments to off-normal operation regime

11. © Olga Ogorodnikova, 2008, Salamanka, Spain Talk outline - T retention in outer vertical target - T retention in inner vertical target - T retention in dome - T retention in FW Normal operation regime

12. © Olga Ogorodnikova, 2008, Salamanka, Spain Vertical target at glancing angle of incidence The particles impinge the surface with a glancing angle of alfa=1  -3 . It will result in high heat and particle fluxes on the edges

13. © Olga Ogorodnikova, 2008, Salamanka, Spain Vertical target at glancing angle of incidence The particles impinge the surface with a glancing angle of alfa=1  -3 . It will result in high heat and particle fluxes on the edges The asymmetrical heat and particle loads as well as asymmetrical cooling result in inhomogeneous temperature distribution inhomogeneous temperature distribution => inhomogeneous T retention

14. © Olga Ogorodnikova, 2008, Salamanka, Spain Erosion due to off-normal events (?) plasma 20 shots @ 1.4 MJm -2 I. Arkhipov, A. Zhitlukhin, Troitsk, RF MK200-U Performance of W under short transient thermal loads

15. © Olga Ogorodnikova, 2008, Salamanka, Spain Influence of off-normal events plasma 20 shots @ 1.4 MJm -2 I. Arkhipov, A. Zhitlukhin, Troitsk, RF MK200-U How much T will be co-deposited (or re- deposited) and where?

16. © Olga Ogorodnikova, 2008, Salamanka, Spain Steady state loads at outer vertical target The total power load consists of about 30% due to irradiation from the plasma and about 70% due to particles heating

17. © Olga Ogorodnikova, 2008, Salamanka, Spain Correlation of the particle fluxes, plasma temperature and power load on outer divertor target Steady state loads at outer vertical target

18. © Olga Ogorodnikova, 2008, Salamanka, Spain Steady state loads at outer vertical target Correlation of the particle fluxes, plasma temperature and power load on outer divertor target

19. © Olga Ogorodnikova, 2008, Salamanka, Spain An increase of the plasma temperature results in -an increase of the density and power load Steady state loads at outer vertical target

20. © Olga Ogorodnikova, 2008, Salamanka, Spain Steady state loads at outer vertical target An increase of the plasma temperature results in -an increase of the density and power load -Shift of a maximum to the strike point

21. © Olga Ogorodnikova, 2008, Salamanka, Spain n-irradiation effect: W max =f(dpa, tem) He ions implantation simultaneously with D ions: influence on D retention and TDS Helium ion bombardment leads to development of the surface relief and destruction of near surface layer Flux dependence Off-normal events and ELM’s should be taking into account R&D

22. © Olga Ogorodnikova, 2008, Salamanka, Spain Embrittlement: W, as typical for bcc metal, after neutron irradiation embrittled due to irradiation hardening and loss of strength at grain boundaries due to contamination by interstitial impurities. Due the high activation of W there is no direct data on the effect of neutron irradiation on tritium retention. Voids: For W despite of low swelling, the vacancy void formation occurs at ~ 400C < Tirr < 1000C and damage dose more than ~ several dpa. Typical structure - superlattice of voids: ~ 5 - 50 nm diameter and lattice parameter ~ 60 - 200 nm n-irradiation effect

23. © Olga Ogorodnikova, 2008, Salamanka, Spain Voids: For W despite of low swelling, the vacancy void formation occurs at ~ 400¡C < Tirr < 1000¡C and damage dose more than ~ several dpa. Typical structure - superlattice of voids: ~ 5 - 50 nm dia and lattice parameter ~ 60 - 200 nm n-irradiation effect Tungsten for ITER divertor - damage ~ < 0.1 dpa, T- 200-1000¡C (with replacement) - no changes of physical properties; - no significant changes at transient events (VDE/disr.); - no changes of erosion; - bulk tritium retention seems low (to be confirmed);