1. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 Co-deposition/Co-implantation R. Doerner, M. Baldwin, G. De Temmerman, D. Nishijima UCSD K. Schmid, Ch. Linsmeier, J. Roth IPP Garching Database on atomic fraction of D in C, Be, W and mixtures Issues with the D/X invariant concept Thermal release behavior Conclusions

2. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 D codeposition with C No systematic data for D in C codeposits at different temperatures exist Data from Doyle is retention in a deuterium saturated carbon surface at different temperatures (in principle the same as a C codeposit)

3. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 D codeposition with C, Be Data from Mayer JNM 240(1997)164 Low arrival rates of Be & D led to oxidation of deposit with water & CO

4. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 D codeposition with C, Be Data from Causey JNM 254(1998)84 Better vacuum conditions led to less O in codeposits and less D retained However, @ 100C – 12% O @ 150C – 3% O @ 200C – 12% O @ 300C – 6% O

5. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 D codeposition with C, Be Data from Baldwin JNM 337- 339(2005)590. Oxygen content in 50C codeposits was 2-3% Oxygen content in 150C and 300C codeposits was 30% O content does not determine D content

6. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 D codeposition with C, Be, W Data obtained in PISCES-B using 85% D & 15% Ar plasma Room temperature W codeposition measured by Mayer JNM 240(1997)164 also concluded a level below a few percent

7. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 D codeposition with mixed, Be/C and W/C, materials becomes less clear Be/C codeposits [Schmid 2005 ITPA] seem to retain D at levels between pure Be & C W/C codeposits [Alimov Phys. Scripta T108(2004)46] seem to retain D similarly to pure W codeposits What is the role of C?

8. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 Focus on Beryllium What variables determine D/Be? Temperature of the layer during deposition seems to be the most important (or at least most consistent) variable Oxygen content may have an influence, but does not solely determine the level of retention in Be codeposited/coimplanted samples Implantation energy of D may play a role Arrival rates of species may be important Other variables, geometry, pressure, layer structure…?

9. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 D/Be does not appear to be an invariant quantity Co-implantation energy alters the level of D/Be Baldwin (50 eV) and cleaner Causey (100 eV) data consistent Both D and Be levels change with energy At similar energy, 3x increase in Be arrival rate results in 3x lower D/Be (X data point) PISCES-B data recently analyzed by IPP X

10. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 If D/X is not invariant, what can we say?

11. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 Thermal removal of D from C codeposits Thermal desorption in vacuum from a-C:H layer created at 200°C [Winter Nucl. Instr.Methods B23(1987) 538] [H/C ~ 0.4 +/- 0.14, in agreement with Doyle]

12. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 Thermal removal of D from Be codeposits Thermal desorption in vacuum from Be/D codeposit created at 150°C [Baldwin JNM 337-339(2005)590]

13. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 Thermal removal of D from W codeposits Thermal desorption in vacuum from W/D codeposit created at 200°C

14. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 Deuterium is released more easily from Be codeposits during vacuum heating [C containing mixed codeposits, Be/C or W/C, retain significant levels of D until heated to high temperature (>500C)]

15. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 Deposition conditions affect layer structure 75 nm Be on Cu @ 300C 6 mTorr D2 ~50% porosity 100 nm W on Cu @ 300C 6mTorr D/Ar plasma Thortons Zone model From Thorton J. Vac. Sci. 11(1974)666.

16. R. Doerner, EU SEWG meeting, JET. July 9-10, 2007 Conclusions/summary The process of co-deposition/co-implantation is still poorly understood The existing methodology of attempting to determine the value of D/X for different ITER materials and mixtures of materials may be flawed Are present co-deposition layers representative of those expected in ITER? Are deposition conditions similar to those in ITER divertor, at ITER first wall? Emphasis needs to be placed on removal of retained D