Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al.,...
-
Upload
riley-mccall -
Category
Documents
-
view
217 -
download
1
Transcript of Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al.,...
![Page 1: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/1.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 1 of 13
Formation of mixed W/C and Mo/C layers in TEXTOR
A. Litnovsky,
V. Philipps, P. Wienhold, S. Richter, K. Krieger,
G. Sergienko, A. Kirscher, A. Kreter, S. Droste, D. Borodin
and TEXTOR Team
![Page 2: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/2.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 2 of 13
Mixed layers in TEXTOR
“Naturally” formed during the PWI experiments
Can be observed after exposure of high-Z limiters
in the SOL plasmas using Limiter Lock systems
Example: twin limiters, castellated limiters
![Page 3: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/3.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 3 of 13
Exposure of twin W/C limiter in the SOL plasmas of TEXTOR*
W content in the deposit is
the largest neat tangency
point
W found deposited locally on
the carbon part of the limiter
*M. Rubel, V. Philipps, A. Huber and T. Tanabe, Phys. Scr. T81 (1999) 61
Deuterium retention only in
carbon deposition area
W deposited in gaps of C
rough surface despite of C
net erosion area
![Page 4: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/4.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 4 of 13
Exposures of castellated limiters: general parameters
Experiment Experiment 1 (Mo castellated limiter II)
Experiment 2(W castellated limiter III)
No. of discharges 39 16
Duration of exposure 219 s. 112 s.
Local Te, eV. ~25 eV ~ 20 eV
Local Ne, cm-3 2.5*1012 6*1012
Averaged fluence 2.0×1020 D/cm2 2.2×1020 D/cm2
Bulk temperature of the limiter 220-260oC 200-250oC
Temperature excursions Local heating of plasma closest edge up to 1600oC
Local heating of plasma closest edge up to 1500oC
Diagnostics used: He beam, fast probe, pyrometers, thermocouples,
video observation system, spectroscopy (D, Mo, W)
![Page 5: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/5.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 5 of 13
0 2000 4000 6000 8000 100000,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
Ato
m d
istr
ibu
tio
n 1
017 a
t./c
m2
Distance, micron
A B
EPMAEPMA
0 100 200 300 400 500 600100
101
102
103
104
105
Thickness, nm
MoCDB
MoCDB
SIMS/DEKTAKSIMS/DEKTAKIntensity, a.u.
~ 75 nm
Investigations of deposited layers: Experiment 1
Plasma flow
AB
A: Plasma facing side of the gap
SIMS (calibrated
with Dektak)
EPMAscan
~ 1.7 mm
~ 1.5 mm
Measured spot (~ 30 nm)
Measured spot (~ 30 nm)
![Page 6: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/6.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 6 of 13
Investigations of deposited layers:Experiment 1: EPMA signals modeling
0 10 20 30 40 50 60 700
50
100
150
200
250D
ep
os
it t
hic
kn
es
s,
nm
Molybdenum share in the deposit at. %
calculated for Carbon
~ SIMS value
At least ~50 at % Mo in the deposit are needed to suit with SIMS results for this location
![Page 7: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/7.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 7 of 13
0 2 4 6 8 10 12 145.0x1016
1.0x1017
1.5x1017
2.0x1017
2.5x1017
3.0x1017
3.5x1017
Distance along the gap, mm
C, at/cm2
Investigations of deposited layers: Experiment 2
Plasma flow
AB
A: Plasma facing side of the gap
SIMS (calibrated
with Dektak)
EPMAscan
~ 1 mmEPMA value
(without W mixing)~ 25 nm
EPMA value (without W mixing)
~ 25 nm
NRA value~ 42 nm
NRA value~ 42 nm
SIMS/DEKTAK value
~ 50 nm
SIMS/DEKTAK value
~ 50 nm
EPMA modeled value (41 at. % W
in the deposit)
EPMA modeled value (41 at. % W
in the deposit)
EPMA, NRA, SIMS/DEKTAK
W castellated limiter
NRAscan
![Page 8: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/8.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 8 of 13
Investigations of deposited layers: Experiment 2
W castellated limiter: W mixing quantification
43,7%
69,6%
2,3%
36%
2,5%
41,6%
3,0%
27,3%
3,5% Observations:
Strong W intermixing on the plasma-closest edges of gaps
(>40 at. % of W);
W-share decreases with the depth of the gap
Looks like more W in plasma-shadowed gaps;
More analyses to follow.
open gap shadowed gapPlasma-
![Page 9: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/9.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 9 of 13
Comparison of the experiments 1 and 2What are these mixed deposits?
Mo/C W/CNMo/NC (gap edge)~ 50 at % Mo NW/NC (gap edge) ~ 40-70 at % W
D/C < 0.1 D/C <<0.1
Less than 0.1% of impinging D
flux trapped in gaps
Less than 0.1% of impinging D
flux trapped in gaps
The properties of W/C and Mo/C mixed deposits are very similar
![Page 10: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/10.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 10 of 13
Comparison of the experiments 1 and 2Similarity of W/C and Mo/C layers: why so?
Same geometry of studied samples
No much difference between Mo and W for EPMA simulation: CKα absorption is similar
Exposure in similar plasma conditions
Y, cm2/mg
Mo W C
19.2 17 6
![Page 11: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/11.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 11 of 13
Comparison of the experiments 1 and 2Similarity of W/C and Mo/C layers: why so? Part II
General feature: metal intermixing decreases with the gap depth
Cn+, D+
C0 , D0
Mo
MoC0, D0
65 at.% Mo* 50 at.% Mo
Very low D content: are W/C layers actually an issue for ITER?
*A. Litnovsky et al, Proc. of 32nd EPS, ECA Vol. 29C, P-
1.015 (2005);A. Litnovsky et al.,J. Nucl. Mater. in
press
![Page 12: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/12.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 12 of 13
Summary
Mixed W/C and Mo/C deposits observed during investigations of twin
W/C limiters and in the experiments with castellated limiters in TEXTOR
Large share of metal (up to 70 at. %) in the intermixed layers
W/C and Mo/C layers formed in gaps of castellated limiters are similar
Metal share in the deposit decreases with distance
from the metal source
Generally low D-retention in studied mixed layers
![Page 13: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/13.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Slide 13 of 13
Thank you
![Page 14: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/14.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Additional slide
NRA spot size
![Page 15: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/15.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Additional slide
W mixing: detailed results
10000 11000 12000 13000 14000 15000
0
10
20
30
40
50
60
70
80
10000 11000 12000 13000 14000 15000
0
10
20
30
40
50
60
70
80 W mixing in the deposit, at. %
plasma open gap er1b
Distance along the gap, micron
plasma shadowed gap er2b
![Page 16: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/16.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Additional slide
SIMS measurement locations
![Page 17: Institut für Energieforschung - Plasmaphysik EURATOM Assoziation – FZJ TEC A. Litnovsky et al., Meeting of the EU TF PWI SEWG on mixed materials, JET,](https://reader035.fdocuments.net/reader035/viewer/2022070305/5514e62f55034693478b59ee/html5/thumbnails/17.jpg)
Forschungszentrum Jülich
in der Helmholtz-Gemeinschaft
Institut für Energieforschung - Plasmaphysik
EURATOM Assoziation – FZJ
TEC A. Litnovsky et al., Meeting of the EU TF PWI
SEWG on mixed materials, JET, Culham, July 9, 2007
Additional slide
Encapsulated deposits*
0 100 200 300 4001x102
1x103
1x104
1x105
Thickness, nm
Intensity, a.u.
SubstrateDepositW-layer D
C
W13C
SIMS spectra show an a:C-D deposit with a
thickness of ~120 nm, covered with a ~ 100 nm thick
layer of pure tungsten
*A. Litnovsky et al., Phys. Scr. T128 (2007) 45;