1 progress in the field of first mirrors a. litnovsky for the first mirror swg
TRANSCRIPT
1
Progress in the field of
first mirrors A. Litnovsky for the First Mirror SWG
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First mirror activity in the
Russian Federation
Compiled by K. Vukolov
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
3
FM activity in RF:1. Choice of material and type of mirrors
2. Development of technologies for fabrication of high quality mirrorsMirrors with Rhodium nanocrystalline coating - N.V. Klassen, this meeting
Mo mirrors with nanocrystalline column coatings – A.V. Rogov, this meeting
Multilayered dielectric mirrors – I.I. Orlovsky, this meeting Large SC Mo mirrors – EU contractFinishing polishing by ion etching – EU contract
3. Study of mirror propertiesLaser test of Mo and Cu mirrors – V.V. Sannikov, this meeting
Sputtering, blistering
4. Deposition and cleaning Research on mirror cleaning in low temperature plasmas – G.T. Razdobarin, this meeting
Heating effect on deposition of H:C films and reflectivity of metallic mirrors – K.Yu. Vukolov, this meeting
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
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I)Table of main results
Activity Result
Large SC Mo mirrors (“Luch”, Podolsk, RF)Mo single crystals of 120-140 mm
Mirrors with Rh coating (IPP, Chernogolovka)
Mirrors with Mo coating (Kurchatov)
Plasma and ion treatment (Kurchatov)
Samples stable under sputtering
Mo mirrors stable under sputtering
Finishing polishing of metallic mirrors
Thermal and Neutron Tests of Multilayered Dielectric Mirrors (Kurchatov)
The mirrors resisted to neutronsup to 1019 n/cm2 and 250C heating
High power YAG-laser test of Mo and Cu mirrors (Kurchatov)
Durability of the mirrors under pulsed laser radiation
Research on mirror cleaning in RF discharge (Ioffe)Heating effect on deposition of H:C films (Kurchatov)
Potential tools for cleaning of in-vessel diagnostic mirrors
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Forschungszentrum Jülichin der Helmholtz-Gemeinschaft
Institut für PlasmaphysikEURATOM Assoziation – FZJ
TEC
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Investigations
at IPP Forschungszentrum
JülichA. Litnovsky for A. Kirschner, A. Kreter, S. Droste,
V. Philipps, P. Wienhold, D. Borodin
and TEXTOR Team.
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Forschungszentrum Jülichin der Helmholtz-Gemeinschaft
Institut für PlasmaphysikEURATOM Assoziation – FZJ
TEC
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interactionlayer
bulk volume
(tungsten)
e.g.: net-erosion
cW(t) cC(t)
C, WC, W
plasma
“Simple mixing surface model” “Surface model of TRIDYN”
plasma
layer 1
layer 2
layer N
e.g.: net-erosion
cW,1(t) cC,1(t)
C, WC, W
cW,2(t) cC,2(t)
cW,N(t) cC,N(t)
Erosion and deposition: surface models
Forschungszentrum Jülichin der Helmholtz-Gemeinschaft
Institut für PlasmaphysikEURATOM Assoziation – FZJ
TEC
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50 100 150 2000
0.02
0.04
0.06
0.08
Electron temperature [eV]
C s
pu
tte
rin
g y
ield
8A20A80Apure carbon
layer thickness d
“simple mixing model”
multi-layer model necessary for
• thin layers• high impact
energies
Necessity of a multi-layer surface model: TRIDYN
Influence of substrate material on the deposition efficiency
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Forschungszentrum Jülichin der Helmholtz-Gemeinschaft
Institut für PlasmaphysikEURATOM Assoziation – FZJ
TEC
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graphite tungsten
4 %Local deposition
efficiency: 0.3 %
Experimental observations: 13C deposition efficiency from injected 13CH4 in TEXTOR
Influence of substrate material on the deposition efficiency
A. Kreter et al, Proc. of 32nd EPS Conference on Plasma Phys. ECA Vol.29C, P-1.014 (2005)
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Forschungszentrum Jülichin der Helmholtz-Gemeinschaft
Institut für PlasmaphysikEURATOM Assoziation – FZJ
TEC
9
“TRIDYN surface model“ vs. “simple mixing model”:► decreased local deposition efficiencies► stronger substrate dependence
TRIDYN surface model is closer to the observations from the experiment
Localldeposition efficiency
13C
experiment
ERO modeling with:
TRIDYN surface model
Simple mixing model
C 4% 2.8% 7.2%
W 0.3% 0.9% 6.3%
Comparison of modeling with experimental results.
Influence of substrate material on the deposition efficiency
Modeling: ERO code coupled with TriDyn
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Forschungszentrum Jülichin der Helmholtz-Gemeinschaft
Institut für PlasmaphysikEURATOM Assoziation – FZJ
TEC
10
New Experiment with Striped C/Mo/W limiter Aim: Further Benchmark of the coupled ERO – TRIDYN code
Picture: Harry Reimertoroidal direction
erosion - zone
deposition - zone
Carbon
Moly
bdenum
Tungsten
Influence of substrate material on the deposition efficiency
Courtesy S. Droste
Ideas: ● Observe carbon background
deposition on different
materials for the direct
comparison;
● Use reproducible discharges;
● Expose the materials under
the same plasma conditions.
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Surface analysis is underway
Forschungszentrum Jülichin der Helmholtz-Gemeinschaft
Institut für PlasmaphysikEURATOM Assoziation – FZJ
TEC
11
Investigations of first mirrors: Current activities
► Direct comparative test of single crystal (SC) and polycrystalline Mo
and W mirrors under erosion conditions: investigations are finished;
► Mirror tests in DIII-D divertor: mitigation of deposition.Deposit quantification with SIMS: done;NRA measurements of C and D on the mirrors;Modeling (collaboration with Jeff Brooks, ANL).
Left Right
4 nm (C)
Down
26.4 nm (C)
~ 91.5 nm (O)*105.6 nm (C)
47.8 nm (C)
On the photo:Deposit thickness distribution on the
mirror exposed in DIII-D divertorResults of calibrated SIMS
measurements
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Forschungszentrum Jülichin der Helmholtz-Gemeinschaft
Institut für PlasmaphysikEURATOM Assoziation – FZJ
TEC
12
Future plans: 2006
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Tests of ITER candidate mirror materials and technologies;► Direct comparative test of SC Mo and Mo mirror with nano-coating in
controlled erosion conditions in the SOL of TEXTOR (collaboration with KI and
Univ. of Basel);
► Direct comparative test of SC Mo, Rh-coated and amorphous mirrors under
erosion conditions in the SOL of TEXTOR (collaboration with KI and Univ. of
Basel);
► Large Mo mirrors for ITER diagnostics (EFDA EU-RF contract)
Carbon transport and the mitigation of deposition on mirrors in a
diagnostic duct: ► Experiment with Periscope-Upgrade system.
Joint experiments: ► New exposure of mirrors in the DIII-D divertor (details later in this
presentation);
► Mirror experiments in the divertor and pump-duct of ASDEX-Upgrade:
presently being discussed.
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Investigations performed
in the University of Basel
and in TCV TokamakCompiled by G. De Temmerman
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
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Exposure of mirrors in TCV Exposure of mirrors in TCV • Mirrors located in the divertor region and recessed below the surface of divertor tiles, no direct contact with the plasma. Simulation of mirrors placed in diagnostic duct;
• No shutter installed at moment but the sample manipulator is electrically insulated from the torus;
• Tests of different candidate materials by pair.
Sample exposures were integrated over short campaign periods of 2-3 weeks, including He glow discharge conditioning
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
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Substrate effect Substrate effect • Test of different materials and different recessment distances
Strong differences in the thickness measured on Si and Mo samples under similar exposure conditions
Thickness determined by ellipsometry/SIMS/ profilometry
Deposited layer consists mainly of carbon and deuterium
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Experiment Material Distance below the tile surface
(mm)
Number of shots
Glow discharge
(hrs)
Deposited thickness
(nm)Mo 1.3Si 15.89
Mo 4
Si24
4
5
50
50
223 24.5
820 90.5
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Mirror research at DIII-D:
status overview D.Rudakov, A. Litnovsky, S.L. Allen, J.A. Boedo,
R.L. Boivin, N.H. Brooks, M.E. Fenstermacher, M. Groth,
C.J. Lasnier, A.G. McLean, R.E. Moyer, V. Philipps,
P.C. Stangeby, G. De Temmerman, W.R. Wampler,
J.G. Watkins, W.P. West, P. Wienhold, C.P.C. Wong.
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
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A new divertor shelf has been installed;
Divertor diagnostics had to be adjusted for the new divertor level;
DiMES mechanism was modified;
New: capability to expose material samples using the mid-plane reciprocating probe drive.
New shelfDiMES
MiMES
MiMES = Mid-plane Material Evaluation System
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
Modified lower divertor in DIII-DDiMES and MiMES
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New mirror experiments in DIII-D
● To repeat the heated experiment at fixed
elevated temperature(150oC) using the existing
DiMES Mirror holder;
● If more machine time available, repeat the non-
heated experiment to study the reproducibility in
the new divertor. DiMES Mirror SamplePFR
150oC
Aims:
The possibility to test other mitigation techniques
ROF Proposal
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
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Modeling: joint activities
of ORNL (USA)
and CEA Cadarache (EU)Compiled by J. Hogan
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
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Validation tests for ITER mirror deposition model
J Hogan*, E Dufour+, P Monier-Garbet+, C Lowry+, E Tsitrone+, R Mitteau+,
* Fusion Energy Division ORNL, + DRFC, CEA-Cadarache
● Deposition on ITER diagnostic mirror depends on the initial rate of generation, transport in the SOL to the mirror and, finally, the local mirror deposition rate;
● A validated quantitative model for the initial generation rate is so far lacking;
● To develop this, the BBQ code is applied to model the complex TS CIEL environment, comparing with local measurements of CII / Da emission from zones in deposition and shadowed regions;
● Results- high Te regime (physical and self-sputter processes) reasonably well modeled;- low Te regime: chemical erosion (J.Roth et al. J. Nucl. Mater 337-339, p.970, 2005) shows low values, but inclusion of sources from intra-tile gaps leads to improved agreement;
A collaboration has started to use ERO code (A.Kirschner (IPP FZJ) et al. to model intra-gap processes.
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
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- Physical, self-sputtering values in range (more work to do on self-sputtering)- Chemical sputtering (D+ flux suppression model*) is too low, Inclusion of measured higher temperatures in intra-tile (gap) region raises Ychem
BBQ validation: comparison
* J Roth et al.,J Nucl Mater, 337-339, p.970, 2005
BBQ calculation of CD4
emission, using IR data for
Tsurf
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
10
10
10
Sputteryield
-3
-2
-1
Yphys (Voie 3)
YselfZ=6 (Voie 3)
10 20 30 40 50
Te(a) eV
Yself (Zone 3)
Yphys(Zone 3)
Channel 3
4
CIEL
R
10 20 30 40 50
10-4
10-3
10
Sputteryield
-2
Te(a) eV
Yphys (Zone 3)
Ychem(Zone 3)without tilegap effects)
Ychem (Zone 3)cases includingtile gapeffects
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Mirror Research at ANL (USA)
Compiled by J. Brooks and J. P. Allain
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
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Status/plans for ITER diagnostic mirror research
J.N. Brooks, J.P. Allain, A. Hassanein, M. Nieto
Argonne National Laboratory
10th ITPA TG on Diagnostics, Moscow April 10-14, 2006
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Erosion/Deposition of ITER diagnostic mirrors: Plans for Code/modeling & Experiments*
We can compute the particle and energy fluxes to the mirrors, and erosion/deposition, as an add-on to planned work on ITER plasma facing component plasma/surface interaction.
Key resources: Code Package OMEGA (edge/sol plasma, sputtering, impurity transport with LLNL), HEIGHTS Code Package (transient response).
We are developing the MC-Mirror code: Monte-Carlo D-T, He, Be transport from plasma, through ducts, to mirrors. Includes sputtering and reflection of/from duct boundaries. Includes helium neutral generation in edge plasma (via charge exchange of He particles reflected from the wall), transport to mirrors Inputs/Connection to MC-Mirror code from Package-OMEGA.) (with University of Wisconsin)
We can compute (via IMD code) the effect on mirror performance.
We can study experimentally, via ANL/PRIME facility, the effects of particles/heat on ITER candidate mirrors.
* Subject to funding.
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ANL Preliminary Tasks: IMD code
IMD (D.L. Windt, Comp Phys 12 (1998) 360) is a computational program that models the optical properties including: reflectance, transmittance, phase shifts and electric-field intensities of multi-layer films and multi-component surfaces;
IMD will be linked with particle-induced damage surface codes;
Preliminary scoping tests of a Au-coated (1.0 µm) mirror with various Be coating thicknesses using the IMD computational code;
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We couple our modeling capabilities with in-house experimental measurements
The Particle and Radiation Interaction with Matter Experiments (PRIME) facility includes:
– State-of-the art in-situ surface metrology (IMPACT experiment) that monitors the behavior of surfaces at various depth scales under high-flux ion irradiation;
– Several ion sources with fluxes 1011-1016 ions/(cm2*sec), 25-500 C, impact angles 0-65 degrees, 5-5000 eV;
– Species: H, D, He, C, N, O, Ne, Ar, Kr, Xe, and Sn; others: C60, Aun
– A full-scale, high-power laser system custom designed and tunable between 193-nm and 2200-nm;
– Up to three ion sources can be run simultaneously. Experience: We have studied extensively the role of energetic ions on
plasma-facing mirror performance used in EUV lithography; This expertise can be leveraged to further understand the role of
particles on first mirrors in ITER and to develop schemes of their protection.
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Example: Sn exposure results on grazing incidence Rh mirrors for EUV lithography
Sn is studied since it is primary EUV radiator candidate for EUV lithography; Experiments at Argonne measure time-dependent erosion rates, Sn implantation and
deposition and in-situ EUV reflectivity; Figure shows surface Sn fraction as Sn vapor is deposited on Rh mirror with about
20% loss of reflectivity at 13.5 nm and 15-degree grazing incidence.
0 5 10 15 20 25 300.5
0.6
0.7
0.8
0.9
1.0
1-1.5 Sn monolayers (~ 0.8 nm)evaporated on Rh mirror
0.75 x 0.81 = 0.61
absolute reflectivity ~ 0.75Measured ex-situ
IMD code: 0.5nm Sn/ Rh, R = 0.63
% o
f ini
tial r
efle
ctiv
ity
Sn exposure time (min)
15-deg +/- 2 deg incidence
0 5 10 15 20 25 300.0
0.2
0.4
0.6
0.8
1.0
surf
ace
Sn
frac
tion
Sn exposure time (min)
Sn on Rh
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Summary
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006
● Significant progress is achieved in the R&D of mirrors for
erosion environment;
● Intensive research is ongoing in the field of mirror cleaning
techniques;
● The mitigation of the deposition at elevated temperatures is
proven to be a complex process, depending on exposure conditions;
● The choice of the substrate (mirror) material strongly influences
the deposition efficiency. This needs to be investigated in future
in more details;
● Good potential and interest in modeling of mirror performance in
ITER, made and planned experiments;
● Closer collaboration with PWI community on issues of common
interest.
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Thank you
A. Litnovsky First mirror SWG Report, ITPA -10, Moscow, April 12, 2006