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Current status of assessment of Tritium inventory in all-W device. O.V. Ogorodnikova and E. d’Agata. Be : port limiter, primary wall, baffle. W : upper vertical targets, dome. Initial plasma-facing materials for ITER divertor. CFC : lower vertical targets. ITER divertor. - PowerPoint PPT Presentation
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© Olga Ogorodnikova, 2008, Salamanka, Spain
Current status of assessment of Tritium inventory in all-W device
O.V. Ogorodnikova and E. d’Agata
© Olga Ogorodnikova, 2008, Salamanka, Spain
Be: port limiter,primary wall, baffle
W: upper vertical targets, dome
CFC: lower vertical targets
Initial plasma-facing materials for ITER divertor
© Olga Ogorodnikova, 2008, Salamanka, Spain
Tungsten
ITER divertorUpper part Inner VT
Upper partOuter VT
Dome
Act as baffles for the neutrals
100 m2
© Olga Ogorodnikova, 2008, Salamanka, Spain
CFC
ITER divertorLower partInner VT
Outer VT
Lower partOuter VT
Interact directly with the scrape-off layer plasma
50 m2
© Olga Ogorodnikova, 2008, Salamanka, Spain
W
ITER divertorLower partInner VT
Outer VT
Lower partOuter VT
Interact directly with the scrape-off layer plasma
50 m2
© Olga Ogorodnikova, 2008, Salamanka, Spain
Vertical Target
W monoblocks(upper andbottom half)
Mario Merola and ITER team
© Olga Ogorodnikova, 2008, Salamanka, Spain
Dome
W flat tiles with HV cooling
Mario Merola and ITER team
- flat tile concept cooled by HV-
© Olga Ogorodnikova, 2008, Salamanka, Spain
First Wall
W
CuCrZr
Mario Merola and ITER team
W macrobrush: W/CuCrZr
Plasma spray W: PSW/CuCrZr
© Olga Ogorodnikova, 2008, Salamanka, Spain
Tritium inventory
Joachim Roth: PSI-18 Toledo, May 26, 2008
© Olga Ogorodnikova, 2008, Salamanka, Spain
Talk outline
- T retention in outer vertical target
- T retention in inner vertical target
- T retention in dome
- T retention in FW
Normal operation regime
Comments to off-normal operation regime
© Olga Ogorodnikova, 2008, Salamanka, Spain
Talk outline
- T retention in outer vertical target
- T retention in inner vertical target
- T retention in dome
- T retention in FW
Normal operation regime
© Olga Ogorodnikova, 2008, Salamanka, Spain
Vertical target at glancing angle of incidence
The particles impinge the surface with a glancing angle of alfa=1-3. It will result in high heat and particle fluxes on the edges
© Olga Ogorodnikova, 2008, Salamanka, Spain
Vertical target at glancing angle of incidence
The particles impinge the surface with a glancing angle of alfa=1-3. It will result in high heat and particle fluxes on the edgesThe asymmetrical heat and particle loads as well as asymmetricalcooling result in inhomogeneous temperature distribution
inhomogeneous temperature distribution => inhomogeneous T retention
© Olga Ogorodnikova, 2008, Salamanka, Spain
Erosion due to off-normal events (?)
plasma
20 shots @ 1.4 MJm-2
I. Arkhipov, A. Zhitlukhin, Troitsk, RF
MK200-U
Performance of W under short transient thermal loads
© Olga Ogorodnikova, 2008, Salamanka, Spain
Influence of off-normal events
plasma
20 shots @ 1.4 MJm-2
I. Arkhipov, A. Zhitlukhin, Troitsk, RF
MK200-U
How much T will be co-deposited (or re-deposited) and where?
© Olga Ogorodnikova, 2008, Salamanka, Spain
Steady state loads at outer vertical target
The total power load consists of about 30% due to irradiation from the plasma and about 70% due to particles heating
-0.2 0.0 0.2 0.4 0.6 0.80
2
4
6
8
10
12
14
particles (70%)
radiation (30%)
total
distance along outer plate, m
Pow
er, M
W/m
2
© Olga Ogorodnikova, 2008, Salamanka, Spain
Correlation of the particle fluxes, plasma temperature and power load on outer divertor target
-0.2 0.0 0.2 0.4 0.6 0.80.02.0x1023
4.0x1023
6.0x1023
8.0x1023
1.0x1024
1.2x1024
1.4x1024
1.6x1024
-0.2 0.0 0.2 0.4 0.6 0.80
2
4
6
8
10
12
-0.2 0.0 0.2 0.4 0.6 0.80
2
4
6
8
10
12
Ele
ctro
n tem
pera
ture
, eV
, or
Heat flu
x, M
W/m
2
distance along outer plate, m
ions
neutrals
4 MW/m2
Power
Te
Steady state loads at outer vertical target
© Olga Ogorodnikova, 2008, Salamanka, Spain
-0.2 0.0 0.2 0.4 0.6 0.80.0
2.0x1023
4.0x1023
6.0x1023
8.0x1023
1.0x1024
-0.2 0.0 0.2 0.4 0.6 0.802468
101214161820
-0.2 0.0 0.2 0.4 0.6 0.802468
101214161820
Ele
ctro
n tem
pera
ture
, eV
, or
Heat flu
x, M
W/m
2
distance along outer plate, m
ions
Te
4 MW/m2
Power
Steady state loads at outer vertical target
Correlation of the particle fluxes, plasma temperature and power load on outer divertor target
© Olga Ogorodnikova, 2008, Salamanka, Spain
An increase of the plasma temperature results in - an increase of the density and power load
-0.2 0.0 0.2 0.4 0.6 0.80.0
2.0x1023
4.0x1023
6.0x1023
8.0x1023
1.0x1024
-0.2 0.0 0.2 0.4 0.6 0.802468
101214161820
-0.2 0.0 0.2 0.4 0.6 0.802468
101214161820
Ele
ctro
n tem
pera
ture
, eV
, or
Heat flu
x, M
W/m
2
distance along outer plate, m
ions
Te
6 MW/m2
4 MW/m2Power
Steady state loads at outer vertical target
© Olga Ogorodnikova, 2008, Salamanka, Spain
-0.2 0.0 0.2 0.4 0.6 0.80.0
2.0x1023
4.0x1023
6.0x1023
8.0x1023
1.0x1024
-0.2 0.0 0.2 0.4 0.6 0.802468
101214161820
-0.2 0.0 0.2 0.4 0.6 0.802468
101214161820
Ele
ctro
n tem
pera
ture
, eV
, or
Heat flu
x, M
W/m
2
distance along outer plate, m
Te
ions 4 MW/m2
17 MW/m2
Power
Steady state loads at outer vertical target
An increase of the plasma temperature results in - an increase of the density and power load
- Shift of a maximum to the strike point
© Olga Ogorodnikova, 2008, Salamanka, Spain
• n-irradiation effect: Wmax=f(dpa, tem)
• He ions implantation simultaneously with D ions: influence on D retention and TDS
Helium ion bombardment leads to development of the surface relief and destruction of near surface layer
• Flux dependence
• Off-normal events and ELM’s should be taking into account
R&D
© Olga Ogorodnikova, 2008, Salamanka, Spain
• Embrittlement: W, as typical for bcc metal, after neutron irradiation embrittled due to irradiation hardening and loss of strength at grain boundaries due to contamination by interstitial impurities.
• Due the high activation of W there is no direct data on the effect of neutron irradiation on tritium retention.
• Voids:For W despite of low swelling, the vacancy voidformation occurs at ~ 400C < Tirr < 1000C anddamage dose more than ~ several dpa.
Typical structure - superlattice of voids:~ 5 - 50 nm diameter and lattice parameter ~ 60 - 200 nm
n-irradiation effect
© Olga Ogorodnikova, 2008, Salamanka, Spain
Voids:For W despite of low swelling, the vacancy voidformation occurs at ~ 400¡C < Tirr < 1000¡C anddamage dose more than ~ several dpa.Typical structure - superlattice of voids:~ 5 - 50 nm dia and lattice parameter ~ 60 - 200 nm
n-irradiation effect
Tungsten for ITER divertor - Tungsten for ITER divertor -damage ~ < 0.1 dpa, T- 200-1000¡C (with replacement)- no changes of physical properties;- no significant changes at transient events (VDE/disr.);- no changes of erosion;- bulk tritium retention seems low (to be confirmed);