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c ar ed h Carbon erosion and transport in the edge of Tore Supra plasmas

Y. Marandet, B. Pégourié, Y. Corre, R. Dachicourt, E. Delchambre, E. Gauthier, H. Roche, E. Tsitrone,

presented by P. Monier-Garbet

Institut de Recherches sur la Fusion Magnétique&

Fédération de Recherches sur la Fusion par Confinement Magnétique

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PWI Tasks

WP09-PWI-04-02/CEA/BSa) Spectroscopic characterisation of carbon erosion and migration

in TS, consolidation of carbon balance from spectroscopy and post mortem measurements

b) Modelling of global carbon, berylllium and tungsten migration using SOLPS.

c) Modeling of carbon migration and fuel retention in Tore Supra.

WP09-PWI-04-02/CEA/PSModeling of carbon migration and fuel retention in Tore Supra. Collaboration with FZJ

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Outline

1. C-gross erosion

visible spectroscopy & imaging

consistency analysis

chemical/ total erosion

2. C-net erosion

cleaning & confocal microscopy

3. Global carbon balance

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C- gross erosion deduced from visible spectroscopy measurements

3

2

Q2b

2

3

Camera field of view

CCD camera+interference filter

+ 4 channel Czerny-Turner spectrometer

(nm)

D 657

D 434

CD 431

CII 427

CII 658.1

Top view of the toroidal limiter

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Good consistency of C part. fluxes from C+ lines at 658nm and 427nm

5

4

3

2

1

06.05.55.04.54.03.5

line averaged electron density (1019

m-2

)

fibre n°1

(1020

C/m2/s)

CII 658nm (S/XB=16) CII 427nm (S/XB=52)

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D particule flux: from D or D ?

Measured ratioD/D~200

2

4

6810

18

2

4

6

6542

4

68

1020

2

4

6

ne (1019

m-3

)

fibre n°1

(ph/m2/s/st)

D D

… while Eirene modeling predicts…

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… while Eirene modeling predicts D/D~ 45-55

and little dependence with plasma parameters

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EIRENE calculations include contribution from molecules + neutral energy distribution

EIRENE calculations include contribution from molecules + neutral energy distribution

2500

2200

35

20

50

45

S/XB for D S/XB for D

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TS42931 : réseau 1200 tr/mm (=431.5nm) Coefficient de calib : 2,1.1012 ph/cps/m2/sr

CD

Dγ

CD molecular band is found to remain smallconsistant with chemical erosion corresponding to less than 5% of total erosion (5% if D from D is used, <1% if D used)

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8/04/08 Y. Marandet et al., Jülich Kolloquium 10

Chemical erosion at low Tsurf?

S. Brezinsek, 2007Tore Supra results consistant with data base (Roth 2004) Textor,

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J. Hogan et al., IAEA 2007

Experimental scaling of total C production

Scaling law for eroded C : C[at/s] ~ 5 1020 (Ptot-Prad)[MW]

5

4

3

2

1

01086420

Ptot (MW)

fibre n°1S/XB=52

C (1020

C/m2/s)

PICRH only (PLH=0)PLH only (PFCI=0)combined heating

Cte C source pattern on limiter across range of injected powerTS42932 t=12s (frame 150)

Sum=1.3e7cpsTS42921 t=12s (frame 75)

Sum=0.66e7cps

250 550

150

450

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Experimental scaling law used to determine total C erosion

Integration of C-generation discharge per discharge

850 g for 3 first CIEL campaigns (2002-2004)

2200 g from 2002 to 2007

Not taken into account…

Erosion on bumpers observed, not quantifiedGlows discharges (J. Bucalossi et al., JNM 313-316 (2003) 263)

100-200 g (5 1024 – 1025 C) for 2002-2007Disruptions (from C. Grisolia, ITPA & F. Saint-Laurent) ~100/year, 100-150 g (5 1024 – 7.5 1024 C)UFOs (~450 during DITS) (size from Ne)

< 1 g for 2002-2007, negligible

Uncertainty of 200-350 g

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Depending on assumptions (CFC: 1.75 g/cm3) 1000-1400 g (5-7 1025 C) of net erosion

Not taken into account…

Lack of knowledge of the original surfaceSignificant variation depending on general slope or not…

? ~700 m

Confocal microscopy during summer 2007 shutdown

Local redeposition = (net erosion)/(gross erosion) ~ 60 %

C- net erosion from confocal scopy

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C- net redeposition

Cleaning of the whole vacuum chamber during summer 2007 shutdown

PFCs surface

before after

also in gaps

790 g (4 1025 C) collected from whole chamber (2002-2007)145 g (7.3 1024 C) on the TPL 645 g (3.2 1025 C) on the other PFCs

Not taken into account…

All scrapped layers collected, deposits in unaccessible areas…

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ConclusionConclusion

• D particule flux: D/D ratio?

• Low level of chemical erosion observed

chemical erosion & Tsurf?

• Local C redeposition rate on limiter ~ 60%

• Global C balance in progress…