SEWG C-Migration, JET, 7-8 July 2009 P. Monier-Garbet 1
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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…