EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ SEWG Chemical Erosion S. Brezinsek TEC 1...
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Transcript of EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ SEWG Chemical Erosion S. Brezinsek TEC 1...
1Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Report of the Special Expert Working Groupon Chemical Erosion
S. Brezinsek
Institut für Plasmaphysik, Forschungszentrum Jülich GmbH, EURATOM Association, Trilateral Euregio Cluster, D-52425 Jülich, Germany
SEWG members:CEA E. Gauthier, J. Hogan …CIEMAT F. Tabares …FZJ A. Pospieszczyk, A. Kirschner, A. Kreter, D. Borodin, G. Sergienko, V. Philipps … IPP W. Jacob, J. Roth, Ch. Hopf, M. Mayer, M. Schlüter, T. Schwarz-Selinger
R. Pugno, A. Kallenbach, W. Bohmeier … UKAEA M.F. Stamp …
2Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECStatus: ITER - tritium inventory limit
0 200 400 600 800 10000
100
200
300
400
500
600
S=0.5,moldyn
S=0,moldyn
Tri
tiu
m c
o-d
ep
oit
ion
(g
)
Number of ITER pulses
Brooks/Kirschner
present evaluation
S=1
In-vessel limit
WBC, PSI 2002
Roth/KirschnerERO, PSI 2004
600 full performance shots!
3Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECFlux dependence of Ychem
• In-situ calibration: mass/optical spectroscopy • Temperature normalisation to Tmax
• Ion energy normalisation to 30 eV• Flux dependence
Roth et al. EPS2003, PSI 2004
Y(E,T,)=
Description of Y as function of- Ion energy- Surface temperature- Ion flux
Ylow(E,T)
6*10211+
0.54
4Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECERO modelling for ITER scenarios
standard ITER operation
Roth, Kirschner et al. NF 2004
•Plasma simulation from B2 Eirene•Steady-state temperature profiles along the divertor target (Federici 2003)
But: No consideration of ELMs, no a-C:H layers,
no synergetic effects …
5Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECTopics to be discussed
Improvement in the data evaluation Better spectroscopic data interpretation Photon efficiencies
Higher Hydrocarbons Influence of
ELMs (e.g. AUG) & detached plasmas (e.g. DIII-D, JET) Geometry and strike-point positions (e.g. JET, AUG)
Erosion of redeposited a-C:H layers (e.g. JET) Synergetic effects
Mixed layers, Be and W (e.g. PISCES) He+, Ar+ (e.g. MAJESTIX), N2 (e.g. JET, AUG)
ERO modelling Benchmark experiments (e.g. PSI-2, TEXTOR)
6Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Improvement in the data evaluation Better spectroscopic data interpretation Photon efficiencies
Higher Hydrocarbons Influence of
ELMs (e.g. AUG) & detached plasmas (e.g. DIII-D, JET) Geometry and strike-point positions (e.g. JET, AUG)
Erosion of redeposited a-C:H layers (e.g. JET) Synergetic effects
Mixed layers, Be and W (e.g. PISCES) He+, Ar+ (e.g. MAJESTIX), N2 (e.g. JET, AUG)
ERO modelling Benchmark experiments (e.g. PSI-2, TEXTOR)
Topics to be discussed
7Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECSpectroscopic data interpretation
Brezinsek,Pospieszczyk et al. 2004
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
CD/D g C /DII g
YChemC
YtotalC
YPhysC
500 750 1000 1250 1500
T / Ksurface
ero
sio
n y
ield
Yin
%c
D : S/XB=507 (ADAS)CD(1.5 nm): D/XB=100 (A.Pos.) CII(426.7 nm): S/XB=87 (ADAS)
gTEXTOR 89155-70
TEXTOR pre-heatable
graphite limiter
New experiments with intensity corrections:Y=3.3 % at Tmax=830 K
Previous experiments(in Roth data base)
Y=4.2 % at Tmax=830 K
Intensity correction:- Photon efficiency correction of Dg due to D2 molecules- Impurity background in the CD spectrum subtracted
8Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Improvement in the data evaluation Better spectroscopic data interpretation Photon efficiencies
Higher Hydrocarbons Influence of
ELMs (e.g. AUG) & detached plasmas (e.g. DIII-D, JET) Geometry and strike-point positions (e.g. JET, AUG)
Erosion of redeposited a-C:H layers (e.g. JET) Synergetic effects
Mixed layers, Be and W (e.g. PISCES) He+, Ar+ (e.g. MAJESTIX), N2 (e.g. JET, AUG)
ERO modelling Benchmark experiments (e.g. PSI-2, TEXTOR)
Topics to be discussed
9Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECHigher Hydrocarbons
Vignettation l-o-s
YC2H4≈ 3.0 %
GIM 10
GIM 9a
b
c
de
JET: C2 light from C2H4 injection
t / s
Higher hydrocarbons only partially treated!
Brezinsek, Stamp 2004
10Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Improvement in the data evaluation Better spectroscopic data interpretation Photon efficiencies
Higher Hydrocarbons Influence of
ELMs (e.g. AUG) & detached plasmas (e.g. DIII-D, JET) Geometry and strike-point positions (e.g. JET, AUG)
Erosion of redeposited a-C:H layers (e.g. JET) Synergetic effects
Mixed layers, Be and W (e.g. PISCES) He+, Ar+ (e.g. MAJESTIX), N2 (e.g. JET, AUG)
ERO modelling Benchmark experiments (e.g. PSI-2, TEXTOR)
Topics to be discussed
11Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECPlasma regimes – H-mode in AUG
Pugno et al. PSI 2004
There is an ion flux dependence in H-mode discharges
Data not normalised!
with ELMs
Integrated over ELMs!
12Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Detached plasmas: still large uncertainties, big scatter of data
-> DIII-D practically no chemical erosion (Whyte et al NF 2001)
-> JET inner divertor: 15% erosion (strike point on vertical target),
less on horizontal target (Stamp 2003)
-> AUG …
-> TEXTOR test limiter: increase of C2 signal! Higher erosion
Effect of rate coefficients?
(Pospieszczyk EPS 1995)
New experiments necessary!
High flux and low energy should reduce the erosion yield!
Plasma regimes – detachment
13Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECGeometry and strike-point positions
1
2 3
57072 57076 57080 570840,0
5,0x1015
1,0x1016
Shot number
2C
arbo
n de
posi
tion
( C
/cm
S
)
11
1
2 2
3
3
1
2 3
1
2 3
57072 57076 57080 570840,0
5,0x1015
1,0x1016
Shot number
2C
arbo
n de
posi
tion
( C
/cm
S
)
11
1
2 2
3
3
57072 57076 57080 570840,0
5,0x1015
1,0x1016
Shot number
2C
arbo
n de
posi
tion
( C
/cm
S
)2
Car
bon
depo
sitio
n ( C
/cm
S
)C
arbo
n de
posi
tion
( C
/cm
S
)
11
1
2 2
3
3
Esser et al. PSI 2004
Strike-point position important Stepwise transport of carbon
QMB – deposition monitor
14Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Improvement in the data evaluation Better spectroscopic data interpretation Photon efficiencies
Higher Hydrocarbons Influence of
ELMs (e.g. AUG) & detached plasmas (e.g. DIII-D, JET) Geometry and strike-point positions (e.g. JET, AUG)
Erosion of redeposited a-C:H layers (e.g. JET) Synergetic effects
He+, Ar+ (e.g. MAJESTIX) on a-C:H layers, N2 (e.g. JET, AUG)
Mixed layers, Be and W (e.g. PISCES)ERO modelling
Benchmark experiments (e.g. PSI-2, TEXTOR)
Topics to be discussed
15Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Sweep of the strike point through the corner in L-mode
0 18time / s20222414123
16
C narrow ch2 C wide ch2
I / 10ph s
cm15
-1-2
a-C:H layers in the inner divertor of JET
Brezinsek et al. PSI 2004
• Strong C2 light emission from hydrocarbon layers => C2Dy
• Different ratio of C2 to CD light • Removal within one discharge in H-mode with strike-point fixed at the location of the layer
a-C:D layer
strike point
14.3 s14.7 s15.0 s
ch3
18Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Improvement in the data evaluation Better spectroscopic data interpretation Photon efficiencies
Higher Hydrocarbons Influence of
ELMs (e.g. AUG) & detached plasmas (e.g. DIII-D, JET) Geometry and strike-point positions (e.g. JET, AUG)
Erosion of redeposited a-C:H layers (e.g. JET) Synergetic effects
He+, Ar+ (e.g. MAJESTIX) on a-C:H layers, N2 (e.g. JET, AUG)
Mixed layers, Be and W (e.g. PISCES)ERO modelling
Benchmark experiments (e.g. PSI-2, TEXTOR)
Topics to be discussed
19Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
UHV chamber
Setup MAJESTIX
H2
CH 3
N2(CH3)2
ellipsometry, infrared
substratesubstrate
preparation chamber
rf plasma H
WienFilter
Ar + 1 keV
Ar + 20 eV
de-celeration
UHV experiment with 2 radical beam sources and one ion beam source
W. Jacob, Ch. Hopf, A. von Keudell, M. Meier, and T. Schwarz-Selinger:” Particle-beam Experiment to Study Heterogeneous Surface Reactions Relevant to Plasma-assisted Thin Film Growth and Etching”, Review of Scientific Instruments 74, 5123-5136 (2003).
Synergetic effects – Ion beam and H
20Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
10 100 1000
0,01
0,1
1
10
chem
ical
spu
tterin
g yi
eld
energy (eV)
N+
2 Ar+
Ne+
He+
H+
2
Combined interaction of ions with atomic H leads to chemical sputtering
here: ratio H/ion = 400
strongly enhanced erosion
Ch. Hopf, A. von Keudell, and W. Jacob, ”Chemical Sputtering of Hydrocarbon Films”, J. Appl. Phys. 94, 2373 (2003).Modeling results: Ch. Hopf and W. Jacob, unpublished, N2 data: M. Meier et al., unpublished
atomic H + ions
Model parameters:a = 0.4R 400
Status:TW4-TPP-ERCARIntermediate Report Jan. 2004
Synergetic effects – chemical sputtering
on hard a-C:H layer
22Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
10 100 1 000
0.1
1
10
1E12
1E13
Hopf's model: = 0.4 nm, E
bb= 5 eV
a = 0.4
eros
ion
rate
=
Y ( Ne+ ), TRIM.SP ( Ne+ ); ( H° )
Y ( Ne+ | H°)
Yie
ld (
erod
ed C
per
ion)
: Y
=
/
ION
Ne+ energy [eV]
M. Schlüter, unpublished
Chemical sputtering yield for the simultaneous interaction of H and Ne+
Good agreement with the model by Hopf et al.
Status:TW4-TPP-ERCARNew results
Synergetic effects – new results
23Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
0 20 40 60 80 1000.00
0.05
0.10
0.15
0.20
0.25
0.30
ero
sio
n r
ate
(n
m s
-1)
N2/(N
2+H
2) ratio (%)
Ion energy 30 eV 50 eV 100 eV 200 eV
Erosion was measured in low-temperature ECR plasmas in mixtures of N2 and H2 (p = 1 Pa).The ion energy was varied by applying an rf bias to the sample electrode.
Steep increase of erosion rate with increasing N2 admixture (factor 15).
Maximum for 20 to 30 % N2.
Slow decrease from 30 to 100 % N2.
Sun Chao, Ch. Hopf, T. Schwarz-Selinger, and W. Jacob, unpublished
Status:TW3-TPP-SCAVOPNew results
New results: Erosion in N2/H2 plasmas
Scavenger experiments performed by Tabares in JET, ASDEX, PISCES => see CIEMAT
24Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
• Expose C target to Be seeded D plasma, Target Bias 50V• Increase Be concentration from 0.0 to 0.15 % during exposure• Monitor Be1+ line and CD-band• Target temperature ~ 500K high chemical erosion
• Expose C target to Be seeded D plasma, Target Bias 50V• Increase Be concentration from 0.0 to 0.15 % during exposure• Monitor Be1+ line and CD-band• Target temperature ~ 500K high chemical erosion
CD-band decreases by ~80% for a Be plasma concentration of 0.15 %
Be surface coverage after exposure 87% (AES).
Indicates shielding effect through Be layer formation
Indicates shielding effect through Be layer formation
Synergetic effects – Be and C
Schmidt et al. PSI 20040.00 0.05 0.10 0.150
20
40
60
80
100
CD
-Ba
nd
inte
ns
ity
[%]
Be plasma concentration [%]
CD-Band intensity [%] Linear Fit: CD = 100.0 - 580.6 * CBe
25Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
0.0 0.1 0.2 0.3 0.40
20
40
60
80
100
Be s
urf
ace c
on
cen
trati
on
[%
]
Be plasma concentration [%]
500K 1000K 1200K 1280K
Be surface concentration increases quickly with Be plasma concentration
Expose C targets to a Be seeded D plasma at:• At target temperatures from ~500K to ~1280K• Be plasma concentrations from 0 to 0.35 %
Measure (AES) Be surface concentration after exposure
At temperatures ≥ 1200K diffusion and thermally enhanced erosion reduce Be surface coverage
Almost full surface coverage for Be plasma concentrations < 1%
Almost full surface coverage for Be plasma concentrations < 1%
Schmidt et al. PSI 2004
Synergetic effects – Be and C
26Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TEC
Improvement in the data evaluation Better spectroscopic data interpretation Photon efficiencies
Higher Hydrocarbons Influence of
ELMs (e.g. AUG) & detached plasmas (e.g. DIII-D, JET) Geometry and strike-point positions (e.g. JET, AUG)
Erosion of redeposited a-C:H layers (e.g. JET) Synergetic effects
He+, Ar+ (e.g. MAJESTIX) on a-C:H layers, N2 (e.g. JET, AUG)
Mixed layers, Be and W (e.g. PISCES)ERO modelling
Benchmark experiments (e.g. PSI-2, TEXTOR)
Topics to be discussed
27Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECERO modelling
- Parallelisation of ERO code
- Improvement of surface model for material mixing (TriDyn)
- Merging of various versions (limiter – divertor – linear devices)
- Including global transport for divertor devices, code coupling??
- Modelling:
• transport of injected hydrocarbons – TEXTOR, JET, AUG(D/XB, deposition efficiency, re-erosion of deposits)
• chemical erosion studies (Roth formula, JET, ITER)
• PISCES (Be-C layers, tungsten)
• formation of mixed layers (dedicated experiments at TEXTOR)
28Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECExample: ERO modelling for ITER
Erosion & re-deposition along outer target: Roth vs. 1% yield
Sticking = 0 for hydrocarbons, MolDyn for atoms
Gross erosion 10 times larger with fixed 1% than Roth yield. Local re-deposition significantly smaller with fixed yield.
with Roth yield:
94% re-deposition
6% loss to PFR
with fixed yield:
80% re-deposition
20% loss to PFR
-2.0x1020
6.0x1020
1.4x1021
2.2x1021 SOLPFRRoth
par
ticl
es [
1/m
2 s]
-0.2 0.0 0.2 0.4 0.6-1.5x10
22
5.0x1021
2.5x1022
fixed (1%) gross erosion re-deposition re-deposition minus gross erosion
distance along outer plate [m]
29Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECERO modelling – PSI-2 experiments
comparison of databases (Erhardt & Langer; Alman, Ruzic & Brooks, Janev & Reiter)
check of sticking coefficients in-situ study of erosion and deposition
Bohmeyer et al. PSI2004
30Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECFuture work
Improvement in the data evaluation Erosion yield for higher hydrocarbons Extension of the plasma parameter regime (detached plasmas) erosion of redeposited layers (a-C:H layer) Synergetic effects
effect of mixed layers, Be and C Chemical erosion He+, N2+ - H mixtures
ERO Modelling TEXTOR and JET methane puffs an hydrocarbon transport,
D/XB values, higher hydrocarbons, PISCES sticking coefficients, data base, PSI-2
31Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting 14.10.04 - FZJ
SEWG Chemical ErosionS. Brezinsek
TECOnline manual on ERO webpage