1. ERO code development A. Kirschner M. Airila, D. Borodin, S. Droste, C. Niehoff  The ERO code  ERO code management  Modelling of CH 4 puffing in ASDEX  Modelling of CH 4 puffing in JET

2. The ERO code  3-dimensional (at present 2D for divertor), Monte Carlo  Various experimental geometries are possible (at the moment: TEXTOR, ASDEX, JET, ITER, PISCES, MAGNUM)  Plasma-wall-interaction: - physical sputtering, chemical erosion (CH 4 or higher hydrocarbons) - C-deposition from background, re-deposition of eroded particles  Local particle transport: - ionisation, recombination, dissociation - Ehrhardt/Langer or Janev data for CH 4 reaction chain - friction (Fokker-Planck), thermal force, Lorentz force, diffusion D 

3. ERO code management (1) Several users and developers: version controlling necessary CVS (Concurrent Versions System) – server at FZJ Variety of versions ERO.LIM ERO.DIV ERO.LINEAR “Main line of development” CVS parallelisation

4. ERO code management (2) Development of user friendly interface (“JERO”) in combination with ERO internet webpage

5. Modelling of 13 CH 4 puffing in ASDEX (1) R [m] Z [m] ERO simulation volume 80° rotation B2-Eirene grid of divertor region

6. ERO simulation volume (outer divertor): separatrix Modelling of 13 CH 4 puffing in ASDEX (2)

7. Modelling of 13 CH 4 puffing in ASDEX (3) Plasma parameter (L mode) from B2-Eirene (D. Coster) separatrix

8. Modelling of 13 CH 4 puffing in ASDEX (4) CH 4 CH 2 CH CH + CC+C+ 0 80 mm 80 mm 0 CH 4 Transport of injected CH 4 into outer divertor @ s=48mm: sticking assumption for hydrocarbons S = 0

9. C-Deposition from injected CH 4 (@ 48mm) into outer divertor: sticking assumption for hydrocarbons S = 0 local deposition: ~70%, losses to PFR: ~30%  PFR SEP SOL  Modelling of 13 CH 4 puffing in ASDEX (5)

10. Modelling of 13 CH 4 puffing in ASDEX (6) Injection of CH 4 (@ 48mm and 88mm) into outer divertor: Puff @48 mmPuff @88 mm S = 0S = 1S = 0S = 1 Deposition at target70%96%89%99.4% Puffing location deeper in SOL: high local re-deposition even if with S = 0!!!

11. Further 13 C transport modelling in ASDEX: in co-operation with M. Airila (Helsinki University of Technology) Modelling of 13 CH 4 puffing in ASDEX (7)

12. Modelling of CH 4 puffing in JET (1) MkIIA: Standard gas fuelled ELMy H-mode, 12 MW (#44029) n e [cm -3 ] 240230250 260220 -170 -160 -150 -140 -130 -180 RC [cm] ZC [cm] 240230250 260220 -170 -160 -150 -140 -130 -180 RC [cm] ZC [cm] T e [eV]

13. Zero sticking of hydrocarbons CD y, Ehrhardt-Langer Location of injection: strike point Profiles of re-deposition for various incoming ion fluxes: Amount of re-deposition: 88% 89% 87% vertical plate base plate Modelling of CH 4 puffing in JET (2)

14. Modelling of CH 4 puffing in JET (3) Amount of re-deposition: 76% 72% 66% vertical plate base plate Zero sticking of hydrocarbons CD y, Ehrhardt-Langer Location of injection: center of base plate (SOL) Profiles of re-deposition for various incoming ion fluxes:

15. Summary: re-deposition of injected CD 4 and C 2 D 4 Injection at strike point:Injection at center of base plate (SOL): No significant difference in re-deposition of puffed CD 4 and C 2 D 4 Puffing at strike point: no significant dependence on flux Puffing at center of base plate (SOL): decreasing re-deposition with increasing flux Modelling of CH 4 puffing in JET (4)