6th ITPA-SOL/Divertor 会议情况介绍

胡建生

10 July, 2005

• July 4-7, 2005• Facultat de Ciències Jurídiques de la Universi

tat Rovira i Virgili• Tarragona, Spain

Main sessions in this meeting

• D/T inventories (surfaces and sides of tiles) & removal• Dust• High-Z experience• Mixed materials effects• First wall loadings & joint meeting with MHD

– Experiment/Modelling of plasma detachment, divertor neutral dynamics and divertor geometry effects.

– Experiment/Modelling of scrape-off layer flows.

• Estimate of the effects of Be operation in ITER• ITER dome

D/T inventories (surfaces and sides of tiles) & removal• Co-deposition

– Recent results on carbon deposition and fuel retention in gaps. – Analysis of C-Mod tiles for B/D co-deposition on tile sides. – Recent results on carbon migration and deposition in AUG. – 13C injection at the outer divertor in JET.

• D/T removal – Recent activities on photo-cleaning in EU. – Oxygen cleaning activities in TEXTOR. – Oxidation wall conditioning in HT-7. – ICRF H/D removal in LHD. – N2 seeding experiments in AUG.

• D/T inventories– Long pulse operation and related wall saturation effects.

Dust

• Modeling – Modeling of dust dynamics and transport in ITER with the c

ode DUSTT. – Modelling of dust formation in plasmas – Modelling of dust dynamics

• Experiment– T-10 results – JT-60 & LHD results. – Detection of dust particles on remote surfaces. – DIII-D results– Enormous quantities of dust in C-Mod and the effects

High-Z experience

• ASDEX Upgrade W operation

• High temperature erosion and melting of W in TEXTOR

• Removal of B from C-Mod and effect of boronization

• W-tile experience from JT-60U and laboratories

• Conclusions about the use of high-Z materials

Mixed materials effects

• IPP results on alloy formation of Be and W

• PISCES Be/C mixed materials studies

• Studies of mixed material erosion/deposition at the Garching dual beam experiment

First wall loadings & joint meeting with MHD

• EU-PWI disruption wall loadings• JT-60U disruption mitigation• C-Mod & DIII-D status of disruption mitigation work• AUG disruption mitigation• JET disruption mitigation• Discussion of first wall loading database• JET ELM measurements/modeling• AUG, DIII-D & MAST measurements of wall fluxes• JT-60U ELM fluxes to walls• Analysis of intermittent transport in JT-60U• Discussion of ELM and disruption wall fluxes

Estimate of the effects of Be operation in ITER

• several Be-wall erosion during steady-state and transient plasma conditions including its spatial distribution

• several Main wall eroded Be migration to the divertor and C/W migration onto the Be wall in ITER

• several Implications of a Be wall on T retention and removal in ITER (including mixed material formation

• several Operability of ITER with a Be main wall/limiter including effect of PFCs damage due to tranients

• Plans and status of Be wall experiment in JET.

ITER dome

• ITER presentation on original strategy for the dome and why to remove it

• ITER calculations of divertor performance with & without dome

• Extrapolation of a diffusive neutral solution to ITER

• Discussion of how to make progress

Proposal for joint research

• Scaling of Type I ELM energy losses. • Hydrocarbon injection to quantify chemical erosion. • Scaling of radial transport. • Comparsion of disruption energy balance in similar discharges (and disruption h

eat flux profiles). • Role of Lyman absorption in the divertor.• SOL flows and influence on impurity shielding. • Study on separatrix density and edge density profiles.• Radial ELM propagation • C13 injection experiments to understand C migration. • Modelling of different gases effects on disruption mitigation power deposition (an

d disruption mitigation experiments on JET and C-mod)• Oxygen wall cleaning. • Carbon deposition measurements in tile gaps.• ICRH wall conditioning.

Next meeting

• China

• Japan

D/T removal• Recent activities on photo-cle

aning in EU. – Good results;– Questions:

• how to control the bulk erosion of carbon during removal;

• Is it a in situ techniques;

• Oxygen cleaning activities in TEXTOR. – O-ventilation; O-GDC and O-I

CR(only one parameters)– Only discussed

• the partial pressure;• removal rate of C, H/D;• Removal of deposited film

– Questions: no water formation observed;

– Oxidation wall conditioning in HT-7. • Focus topics

– Removal rate of C, H/D;– The influence of

parameters;– Oxygen retention;– How to remove oxygen;– Recovery of plasma;– Prediction for ITER;– The physics of

oxidation;– The removal of co-

deposition.• Suitable methods and Good

results• Question:

– The location removal;

Questions for fuel removal

The possibility of adopting in ITER is still uncertain.

1. Wall material in ITER?

2. Plasma recovery?

What heating method is most promising?

How to remove dust?

How much can we use plasma heating to reduced T/Be, C fraction on PFC sides?

Oxygen: Possible in an Be dominated enviroment, such as for C-removal at remote access?

C-Oxidation also possible in C-layers with same B?

How can we remove fuel from Be-rich layers with some C?

Wall saturation and density control is a real issue for ITER?

Removal rates and applicably to various material and hidden areas?

Dust discussion

• What is the role of dust in:

– Core contamination

– Impact on plasma transport

– T retention and transport

– PFM transport, erosion, Re-deposition

• Physics issues:– Dust formation(where, when and how)

– Dust dynamics in tokamak plasma(forces, erosion/growth, etc)

– Dust interactions with surface;

– ?

Discussion of High-Z experiment

• Would we dare to built a full tungsten burning device;

– As early as ITER in T phase

• Restriction in operation

• Fuel retention

Discussion of mixed material session

• Be-W system– Potential for major malfunction.

– Must Be discussed under the most likely ITER scenario.

• Be-C system– Be reduced chemical erosion of C;

– What is inflence on T retention? Similar co-deposition at 300K, but release at lower temperature

• W-C system– W erosion enhanced by C impurities.

– W eroded by C ions, C removed by D ions.

Discussion of Boronization

• Boronization in case of a Be-free device?

• What is the effect of boronization?

• We do not realy know?

• How long does last?

• Other techniques of wall conditioning?

• Just for oxygen reduction?

• Operation with full W without wall conditioning?

First wall load discussion

• Disruption power loads on first wall– Physics guidelines for disruption thermal loads

• Need recommendation to CC

– How do we resolve the big variability between machines?

• Is this different physics, diagnostic difference, difference of definition?

• On one machine for one type disruption?• Vapour shielding impact?• First wall or divertor where do do need guidelines?• Loads at non active divertor?• Do we have any information on first wall loads at all?

Disruption mitigation

• Do we need it at all?

• Mitigation pros and cons is really to login?

• What is the quality of disruption predication to go with it?

• Depend on disruption type?

• Possibly of increased eddy force even if low halo forces?

• Is mitigation suitable for e.g. at scenarios?

• Is Q=2 surface reachable in ITER?

• Disruption mitigation scenarios and guidelines for the design of mitigation system-need recommendation.

ELM power loads on first wall

• Impact of hot ions on high-Z wall.• Still issues of how for MHD radial pertardation• Does filament model mean well flux only on limit

er?• Does it fell as anything about the limiter design?• Over what area is the energy deposited?• What’s the impact of rotation.

Erosion/deposition in HT-7-in 32th EPS meeting

• 总共有 14人感兴趣 ;• 同样的现象在很多装置都已经发现 :

– 表面沉积与腐蚀分布 ;– 极向限制器边上及内衬上的 Flake;

• 多人表示要用我们的图片做分析 ,了解其生长过程 ;– Dust;– Thick film;

• 将 HT-7 结果收集在 DATA BASE 内 ;– For ITER

总体印象• 安排紧凑 ;

• 主题明确 ;

• 讨论激烈 .