Download - 1 E. Delchambre Demoncheaux Culham (22/07/08) Euratom CARBON SOURCES IN TS LONG DISCHARHES
1E. Delchambre Demoncheaux Culham (22/07/08)
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CARBON SOURCES IN TS LONG DISCHARHES
CARBON SOURCES IN TS LONG DISCHARHES
2E. Delchambre Demoncheaux Culham (22/07/08)
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EXPERIMENTAL SET-UPEXPERIMENTAL SET-UP
3E. Delchambre Demoncheaux Culham (22/07/08)
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CCD
4 fibers linked to a Czerny-Turner spectrometre
JAI CCD camera (filters wheel)
Filters wheel(Dα, C2, C+, CD)
VISIBLE IMAGING SYSTEM (1/2)
Splitter cube
Materialisation of fibre views
erosion area
erosion area
D434.0 nm
CD 430.7 nm
38799C+ 426.7 nm
wavelength
Bandwidth 15 Å
optical fibres validate filtered images
CCD and spectrometer system both calibrated in situ with labsphere
4E. Delchambre Demoncheaux Culham (22/07/08)
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JAI CCD camera (Dα fixed filter)
VISIBLE IMAGING SYSTEM (2/2)
fibre bundle
38056Dα
High field side
Low field side
1) Upgrade of the diagnostic: system multi – cameras simultaneous C+, Dα, CD, better spatial resolution, higher frequency acquisition and programmable exposure.
1) Upgrade of processing tool WOLFF (developped by G. Dunand & V. Moncada)
TPL view of the new system
5E. Delchambre Demoncheaux Culham (22/07/08)
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WOLFF (Warping toOL For Fusion) is a quantitative imaging processing tool for IR and visible cameras.
1) Superimpose on the real geometry (images from same camera with/without no filter) validate CCD with fibres
IMAGING PROCESSING TOOL
Materialisation of fibre views
erosion area
erosion area
1
23
4
Dα emission
38803 @ 6 s
2) Warping technique allows to superimpose images taken on the same object with cameras with different angle of view.
HR IR image
6E. Delchambre Demoncheaux Culham (22/07/08)
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α
TPL
SOL
α = 0Contact point between the limiter and the LCFS
NET EROSION ZONE
DEPOSIT ZONE
SHADOWED AREA
poloidal cut of interaction plasma/limiter
EROSION DEPOSITION PATTERN
Contact point between the limiter and the LCFS
Magnetic configuration (plasma shape & ripple) determines the toroidal heat flux pattern therefore the erosion/deposition pattern
7E. Delchambre Demoncheaux Culham (22/07/08)
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C sources: erosion area + leading edge + gap . Growth of deposits
CII
Ha
CII & Ha Emission Evolution
CII
Ha
Beginning of DITS campaign (+ 183 shots) End of DITS campaign
39748 @ 40 s 39931 @ 40 s
8E. Delchambre Demoncheaux Culham (22/07/08)
EuratomGROWTH OF DEPOSITS C2 553 nm & IR
39774 @ 40 s 39930 @ 40 s
9E. Delchambre Demoncheaux Culham (22/07/08)
Euratom
Need to increase acquisition rate: 1 frame/s 15 frames /sec
Tangential zone: deposition/erosion zone (consistent with with TEXTOR results on the Alt-II limiter
Material migration: dust deposited on tile
CD 39836 @ 7.9 s
CD 39836 @ 8.9 s
CD 39836 @ 9.9 s
10E. Delchambre Demoncheaux Culham (22/07/08)
Euratom
39800
DITSCD Emission
Zone of deposits which. consistent with TEXTOR [P. Wienhold et al., Journal of Nuclear Materials, vol.313-316 (2003) p.311-320 (2003) ]
39760 @20s 39855 @20s 39862 @20s
11E. Delchambre Demoncheaux Culham (22/07/08)
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disturbance from thermal photons ? No, but corelation with a local increase of Tsurf
CD Emission ?
Correlation with LH heating Supra thermal electron ? CD emission ? Need to be spectrally
resolved fiber views now looking at this area
R. Mitteau, L. Colas, Note de travail, CH/NTT-2003.003
Supra thermal electron generated by LH heating which circulate on the LCFS and might intercept deposits in the tangential area. Scaling in PLH/n for those electron experiment
Intercepted surface by electron as a function of the heat flux decay length decay length
12E. Delchambre Demoncheaux Culham (22/07/08)
Euratom
CII (6578A)
2,00E+18
7,00E+18
1,20E+19
1,70E+19
2,20E+19
39750 39800 39850 39900 39950 40000 40050
chocs
bri
lla
nc
e (
ph
oto
ns
/m².
s)
VD1 VD2 VD3 VD4Max of CII emission on VD1 and VD3
VD1
VD2VD3
VD4
CII emission – optical fibres views
2MW LH1.2 MW LH
13E. Delchambre Demoncheaux Culham (22/07/08)
Euratom
Ha (6570 A)
2,00E+20
2,50E+20
3,00E+20
3,50E+20
4,00E+20
4,50E+20
5,00E+20
5,50E+20
6,00E+20
6,50E+20
7,00E+20
39750 39800 39850 39900 39950 40000 40050
chocs
Bri
llan
ce (
ph
oto
ns/
m².
s)
VD1
VD2
VD3
VD4
Highest D photon flux on deposits zone and an increase of 20 %
Ha emission – optical fiber views
2MW LH1.2 MW LH
Modification of the recycling coefficient at the surface ?Modification of the release mechanism ? not straightforward need clarification.
VD1
VD2VD3
VD4
14E. Delchambre Demoncheaux Culham (22/07/08)
Euratom
[S/XB] Hα = (15-20) * 2 (molecular contribution) = 30
[S/XB]CII (5678A) = 10
Total erosion yield of about ~ 2 % on net erosion area. No variation observed during the campaign
Erosion yield (Ha & CII 658 nm)
VD1
VD2VD3
VD4
Low signal. Long integration time Ychem = CD/Dg < 1 %
Difficult to conclude on chemical erosion contribution
[S/XB] Hγ = 1000
[D/XB] CD = 2.8*25 (Te~20-30eV) = 65
15E. Delchambre Demoncheaux Culham (22/07/08)
EuratomCONCLUSIONS
Carbon sources identified on erosion zone, leading edge and radial gap tiles.
Growth of deposits observed in CII, CD and Dα with highest Hα emission on deposits which increases during the campaign.
Strong radiative activity in tangential area observed with CD filtered during LH heating probably related to flaking of deposits in this region need spectrally resolved observation with new fibres views
Ytot deduced from CII(568nm)/Hα ~ 2 % BUT no comparison available with CII(426nm)/Dγ since issues with CII lines mentionned yesterday was highlited after DITS campaign Issue under investigation
16E. Delchambre Demoncheaux Culham (22/07/08)
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ADDITIONAL SLIDESADDITIONAL SLIDES
17E. Delchambre Demoncheaux Culham (22/07/08)
EuratomRADIAL PROFILES
Physical erosion seems dominent
CIICD
Dγ
18E. Delchambre Demoncheaux Culham (22/07/08)
Euratom[S/XB] CII426nm, CII658nm (ADAS)
CII 658 nm
CII 426 nm