1. 1 3rd meeting Working Group 5

2. 2 Agenda WG5 2nd Meeting Agenda: Discuss existing proposals Indicate missing proposals Allocate persons to develop proposals until July meeting Overlap with other WGs Dates / Miscellaneous

3. 3 Exiting Proposals WG5.1Reducing W sputtering by GD nitride formation (P. Tabares) Needs further elaboration, closely connected to WG10.15,WG10.18 May be moved to WG10, Request for possibility of N GDC passed to operator WG5.2 Monitoring of intrinsic impurity content (G. Maddison, H. Weisen et al.) quite elaborated, using monitoring discharges, partly parasitic, WG5.3 Develop and Optimise Fuelling Techniques to Control/Avoid Tungsten Accumulation (D. Frigione et al.) some elaboration needed, could accommodate influence of seeding gas, closely connected to WG5.6

4. 4 Exiting Proposals WG5.4 Determination and control of the intrinsic impurity composition in the full W divertor (S. Brezinsek) Needs further elaboration, could accommodate influence of seeding gas, closely connected to WG10.17 and WG10.20 WG5.5 Characterisation of evolution of C, Be and other light impurities concentration (C. Giroud) Mostly parasitic, may be merged into WG5.2 WG5.6 Characterisation and control of impurity production, transport and contamination(C. Giroud) some elaboration needed, use of trace injections, complements for tungsten WG5.3 (concentrates on sources and edge transport, but for all intrinsic impurities)

5. 5 Exiting Proposals WG5.4 Determination and control of the intrinsic impurity composition in the full W divertor (S. Brezinsek et al.) Needs further elaboration, could accommodate influence of seeding gas, closely connected to WG10.17 and WG10.20 WG5.5 Characterisation of evolution of C, Be and other light impurities concentration (C. Giraud) Mostly parasitic, may be merged into WG5.2 WG5.6 Characterisation and control of impurity production, transport and contamination(C. Giraud) some elaboration needed, use of trace injections, complements for tungsten WG5.3 (concentrates on sources and edge transport, but for all intrinsic impurities)

6. 6 WG5.7 Study of central heating techniques to minimise/prevent Tungsten accumulation (D. Frigione et al.) some elaboration needed, can partly performed jointly with WG 2.1 and WG 3.4 WG5.8 W Divertor Retention (R. Dux et al.) some elaboration needed, can partly performed jointly with WG 5.4, 5.6 and and WG10.17, 10.20 WG5.9 Conditions for tungsten peaking and accumulation (H. Weisen et al.) quite elaborated, prerequisite for WG5.3 and WG5.7

7. 7 Projection of ideas to proposals WG5.1x: 2.1,2.2WG 5.2 (WG 5.5) Behaviour of Be concentrations (in comparison to C with C wall), use reference discharges from pre ILW campaigns WG5.2x: 2.3WG 2.1, WG 5.6 Behaviour of Be influxes, concentrations in different RF heated scenarios (in comb. with WG5.5x) WG5.3x: 3.1WG 5.2 Monitor W influxes, concentrations in different discharge scenarios (mostly parasitic) WG5.4x: 3.2WG 5.8, WG 5.6 Role of ELMs for W concentrations WG5.5x: 3.3WG 5.8 W divertor retention, role horiz./vert. target (bulk/coating) WG5.5x: 3.4WG 5.9 Conditions for W peaking /accumulations WG5.5x: 3.5WG 2.1, WG 5.6 Behaviour of W influxes, concentrations in different RF heated scenarios (in comb. with WG5.2x), WG5.6x: 3.5WG 5.9, WG 5.7 Develop RF heated scenarios for W accumulation mitigation WG5.7x: 3.6WG 2.1, WG 5.6 Compatibility of W mitigation compatible with other ICRH application goals WG5.8x: 4.1WG 10.17, 10.20, WG5.8, WG 5.4 change of transport should be covered explicitly Monitor intrinsic impurity influxes and concentrations in different impurity seeded discharge. Perform specific discharges to disentangle source and transport effects WG5.9x: 5.1WG 5.6 Monitor intrinsic impurity influxes and concentrations for different ELM mitigation techniques. Perform specific discharges to disentangle source and transport effects

8. 8 Missing Items Role of transport change in seeded scenarios (N/Ne/Ar) Integration to find optimum with respect to impurity sources / transport and plasma performance Close links to WG 14! How do the tools extrapolate to ITER?

9. 9 Additional overlap with other WGs WG 6.18Comparison of plasmas with strong Be evaporation and Be first wall with respect to impurity concentrations, content and fluxes (S. Brezinsek) WG10.15W erosion amelioration due to nitride formation at the target plates WG10.17W and Be erosion due to extrinsic impurities injected into main chamber and divertor WG10.18Study of BeN formation in the main chamber and divertor with usage of N as seeding species WG10.20Be and W erosion in plasmas with combined seeding of N and Ne/Ar - synergetic effects Rest: see links on WG5 Wiki page

10. 10 Wishlist for elaboration of proposals Approximate number of sessions Heating scenarios / power Current / field Shaping Scarces resources Define milestones for execution of proposals Allow TFLs estimate for needed session Allow TFLs draft of execution sequence

11. 11 Miscellaneous Dates for next meeting: E1/E2 review meeting: 8/9 July How 28/07/2010 13:00 K1/0/38