1. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010 Report on: WP10-PWI-01-01-01/IPP/PS Multi machine scaling of fuel retention for ITER Validation of the assessment procedure for inventories from the underlying retention processes for different tokamaks, such as ASDEX Upgrade, Tore Supra and JET. Extension of the multi machine scaling of fuel retention to ITER (AUG, TS, TEXTOR (JET for comparison), other relevant devices, PSI devices). ASDEX Upgrade J. Roth, M. Mayer, K. Sugiyama, K. Krieger, V. Rohde, A. Kallenbach, Tore Supra E. Tsitrone, C. Brosset, T. Dittmar, E. Gauthier, T. Loarer, J. Bucalossi TEXTOR V. Philipps, S. Brezinsek, A. Kirschner, A. Litnovsky, PISCES R. Doerner, M. Baldwin Benchmark predictions for Carbon against present day tokamaks Validate methodology for all-W ASDEX Upgrade

2. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010 First part:

3. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010

4. (for comparison)

5. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010

8. for carbon PFCs (particle balance)

9. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010 Fuel retention in all-W machines Only one machine available for validation of methodology: AUG Particle balance from literature: (V. Rohde, NF 49(2009)085031) long term retention 4% of injected about 2 ± 1.5 g/h Integration over 30 discharges compared with 23% in all carbon Post-mortem results in dominantly divertor retention of 0.2 ± 0.1 g/h (K. Sugiyama, NF 50(2010)035001 Retention reduced by about a factor of 10 Fluxes (at/s) Inventory (at)

10. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010 all-W AUG gas balance post-mortem all-carbon AUG Fuel retention in all-W machines Only one machine available for validation of methodology: AUG Particle balance from literature: (V. Rohde, NF 49(2009)085031) long term retention 4% of injected about 2 ± 1.5 g/h Integration over 30 discharges compared with 23% in all carbon Post-mortem results in dominantly divertor retention of 0.2 ± 0.1 g/h (K. Sugiyama, NF 50(2010)035001 Retention reduced by about a factor of 10

11. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010 Crucial input data for scaling fluxes to PFCs (see above) retention data vs. temperature, energy, fluence Is there good evidence for retention saturation? 30 g

12. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010 Simple scaling from AUG to ITER using fluxes to PFCs (see above) Reasonable agreement with post- mortem data For one hour almost linear increase in retention with PFC flux both, for all carbon and all W Wall retention determines ITER inventory after long times. For one hour no saturation yet for ITER retention. AUGITER all carbon all W flux

13. J. Roth, EU PWI TF, SEWG Fuel Retention, Garching, July 19, 2010 Conclusion for W PFCs scaling methodology benchmarked for all-W ASDEX Upgrade reasonable agreement within error bars for post-mortem campaign inventory gas balance depends strongly on particular discharge, inventory assessment requires long (>45 s) integration times Extrapolation to ITER: 1-3 g T in first hour, non linear, saturation below 50 g T total Next step: benchmark for W and Be: JET ILW Status report, evaluations ongoing Discussion data ranges covers fluences expected for the ITER wall lifetime non-linear increase with time (α t 1/2 ) saturation at high fluences additional effects due to n-damage needs to be assessed α t 1/2 saturation