Post on 27-Mar-2015
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
PWI activities at CIEMAT (Madrid)PWI activities at CIEMAT (Madrid)
presented by F. Tabaréspresented by F. Tabarés
Laboratorio Nacional de Fusión por Confinamiento Laboratorio Nacional de Fusión por Confinamiento
MagnéticoMagnético
Asociación EURATOM/CIEMAT. Madrid.Spain Asociación EURATOM/CIEMAT. Madrid.Spain
EU-PWITF. Ljubljana 13-15 Nov. 2006EU-PWITF. Ljubljana 13-15 Nov. 2006
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
OUTLINOUTLINEE-Wall conditioning of TJ-II
-Carbon erosion studies in TJ-II
- Particle transport studies in TJ-II
- Removal/inhibition of carbon co-deposits
-Scavengers: Laboratory studies
JET experiments
-Oxidation, plasma assisted techniques
-Wall conditioning of TJ-II
-Carbon erosion studies in TJ-II
- Particle transport studies in TJ-II
- Removal/inhibition of carbon co-deposits
-Scavengers: Laboratory studies
JET experiments
-Oxidation, plasma assisted techniques
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Wall conditioning of TJ-IIWall conditioning of TJ-II
TJ-II Stellerator (R=1.5 m, a <0.23 m, B=1T)Boronisation at beginning of the exp. campaign4 gr o-carborane in He GD B/C ~ 50nmHe (Ne) GD 30 min at beginning of experimental day.ECRH plasmas (up 600 kW): good impurity control (Z~1) and acceptable density control.NBI plasmas (up 400 kW): uncontrolled increase of density
We need a good H2 and O2 getter
Lithium coating
TJ-II Stellerator (R=1.5 m, a <0.23 m, B=1T)Boronisation at beginning of the exp. campaign4 gr o-carborane in He GD B/C ~ 50nmHe (Ne) GD 30 min at beginning of experimental day.ECRH plasmas (up 600 kW): good impurity control (Z~1) and acceptable density control.NBI plasmas (up 400 kW): uncontrolled increase of density
We need a good H2 and O2 getter
Lithium coating
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
First test of Lithium First test of Lithium coatingcoating
4 Lithium ovens: 2 fixed (side windows) and 2 in retractable
manipulators (top windows)
4 Lithium ovens: 2 fixed (side windows) and 2 in retractable
manipulators (top windows)
1 gr of Li per oven, heated to ~600 ºC during Ne GD1 gr of Li per oven, heated to ~600 ºC during Ne GD
Emission of Li injected froma retractable oven
Emission of Li injected froma retractable oven
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
First test of Li coatingFirst test of Li coating
Problems:-Lack of good temp. control in the inserted ovens: strong asymmetry of deposited Li.-Accidental venting of TJ-II with N2. Production of Li3N ??
Results: ECRH plasmas (N plasmas?) with a poor density control. Very low H fuelling required
Next campaign: 4 fixed oven.More lab. work in order to improve the coating:Li + He/Ne GD (simultaneous or consecutive)
Problems:-Lack of good temp. control in the inserted ovens: strong asymmetry of deposited Li.-Accidental venting of TJ-II with N2. Production of Li3N ??
Results: ECRH plasmas (N plasmas?) with a poor density control. Very low H fuelling required
Next campaign: 4 fixed oven.More lab. work in order to improve the coating:Li + He/Ne GD (simultaneous or consecutive)
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
C-film formation and erosion in TJ-IIC-film formation and erosion in TJ-II
CH4 and C2H4 have been injected at the plasma edge using a mobile, instrumented limiter, producing local C-films. Identical (reference ) limiter at 180 º(PSI-2006 to appear J. Nucl. Mat.)
CH4 and C2H4 have been injected at the plasma edge using a mobile, instrumented limiter, producing local C-films. Identical (reference ) limiter at 180 º(PSI-2006 to appear J. Nucl. Mat.)
-C2H4 presents much lower fuelling efficiency than H2
-C2H4 yields only a 15% of H/Hatom compared with H2
-CH/H 3x higher in C2H4 vs CH4
-C2H4 presents much lower fuelling efficiency than H2
-C2H4 yields only a 15% of H/Hatom compared with H2
-CH/H 3x higher in C2H4 vs CH4
-0.2 0 0.2
-0.36
-0.24
-0.12
0
0.12
R-R0 (m)
Z (
m)
CH emission
gass-puff hole
H limiter
-C2H4 injection producedC-layers with high H content(from particle balance)-No difference in erosion between methane/ethylene layers-Physical sputtering dominant
-C2H4 injection producedC-layers with high H content(from particle balance)-No difference in erosion between methane/ethylene layers-Physical sputtering dominant
ResultsResults
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Erosion of local C-layersErosion of local C-layers
Comparison of erosion of the deposited films by plasmasfed by limiter puffing or by machine puffingComparison of erosion of the deposited films by plasmasfed by limiter puffing or by machine puffing
Global contamination ofthe full wallGlobal contamination ofthe full wall
Higher erosion by plasmasfeed away for the limiterHigher erosion by plasmasfeed away for the limiter
0
1
2
3
4
5Summary of ethylene injection/erosion
CHC
Inte
ns
ity
(a
.u)
Clean limiterz=-10 Puff z=-10 Plasma z=-15 Puff z=-15Plasma
CHinject.
Reference: z=-10Puff. H2 in cleanlimiter
0
2
4
6
8
10
15280 15285 15290 15295 15300 15305 15310 15315
Inte
nsi
ty (
a.u
)
Shot#
CH/ne
CV/ne
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Other studies in TJ-IIOther studies in TJ-II
Transport StudiesImplementation of EIRENE code to the TJ-II geometryBy J. Guasp & A. Salas. Applications:-Simulation of He ECRH plasma using He emission lines of3 different . Neutral profiles obtained. (EPS-2006)-H profile modeling. (E. de la Cal PSI-2006).
DiagnosticsTesting of He C-R model by a supersonic He beam.Sensitivity of model to rate constant uncertaintiesUse of LIF for change population in collisional-coupled levels and estimate the rates of transition with n=0.(A. Hidalgo et al. PPCF 48 (2006) 527.
Transport StudiesImplementation of EIRENE code to the TJ-II geometryBy J. Guasp & A. Salas. Applications:-Simulation of He ECRH plasma using He emission lines of3 different . Neutral profiles obtained. (EPS-2006)-H profile modeling. (E. de la Cal PSI-2006).
DiagnosticsTesting of He C-R model by a supersonic He beam.Sensitivity of model to rate constant uncertaintiesUse of LIF for change population in collisional-coupled levels and estimate the rates of transition with n=0.(A. Hidalgo et al. PPCF 48 (2006) 527.
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Modeling of He plasmas by EIRENE in TJ-IIModeling of He plasmas by EIRENE in TJ-II
radii Z(cm) Pixel1 0.614 22.3 12 0.725 23.1 33 0.737 24.3 64 0.840 25.1 85 0.898 26.3 116 0.961 27.1 13
706 nm
728 nm
667 nm
Simultaneous detection by3 arrays of 16 PMTs
-EIRENE neutral code (2) adapted to TJ-II geometry: First case.- 9.6 M trajectories for neutral He followed.- Statistical uncertainty 3% in the He line ratios. - He line ratios insensitive to most of the model parameters.- He line ratios very sensitive to ne and Te edge profiles- Edge profiles adjusted, inside the experimental error limits, for the best fitting.
0
2 1012
4 1012
6 1012
8 1012
1 1013
0 0,2 0,4 0,6 0,8 1
Plasma densityshot #11245
dens
ity (c
m-3
)
r/a
Mofidied
Original
0
200
400
600
800
1 103
1,2 103
0 0,2 0,4 0,6 0,8 1
Plasma Temperatureshot #11245
Tem
pera
ture
(eV)
r/a
Mofidied
Original
The edge profiles from Thomson Scattering and He-beam in H plasmas are a starting point for the simulation
Dotted lines: exp. error limits (20%)Continuous lines: statistical uncertainty of EIRENE (3%)Edge parameters: ne=1.09x1012 cm-3, Te= 41 eV
Good Fitting with smooth edge profiles
Neutral profiles:Absolute calibration of 667 nm He line (error 50%)
Adjust parameters:Ne(a) = 1.09x1012 cm-3 ( 8%)Te(a) = 41 eV ( 4%)Ti(0) = 80 eV ( 24%)Ti(a) = 25 eV ( 10%)He+/He++ = 90% ( 10%)p = 5.6 ms ( 20%)
0
2 1010
4 1010
6 1010
8 1010
1 1011
0 0,2 0,4 0,6 0,8 1
Neutral density Helium
shot #11245, enl = 0.64x1013 cm-3
Perf_He
Expon. Fit1
Expon. Fit2den
s. (
cm-3
)
r/a
Edge= 9.3x1010 cm-3
Rel. Edge/Center = 51
10%
38 %
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Validation of the C-R model for He in a supersonic He beam in TJ-IIValidation of the C-R model for He in a supersonic He beam in TJ-II
0
2 1012
4 1012
6 1012
8 1012
1 1013
1.2 1013
0
20
40
60
80
100
0.75 0.8 0.85 0.9 0.95 1
#13567
ne
Te
n e(c
m-3 ) Te(eV
)
0
0.5
1
1.5
2
2.5
3
3.5
0.75 0.8 0.85 0.9 0.95 1
#13567
I667expI706expI728exp
I667simulatedI728simulatedI706simulated
I(a.
u.)
0 1m
HeTurbopumps
Observationoptics
He beam
pulsed valve & skimmer
=85,3°
Manometer
PLASMA
VACUUMVESSEL
LASER
Vacuum chamber 1
Vacuum chamber 2
0
200
400
600
800
-0,8 -0,6 -0,4 -0,2 0 0,2 0,4 0,6 0,8
ThomsonECEHaz de He
Te(e
V)
0
200
400
600
800
1000
1200
1400
-1 -0.5 0 0.5 1
13574
Sonda de LangmuirThomsonHaz de He
T e(e
V)
0
2 1012
4 1012
6 1012
8 1012
1 1013
1,2 1013
-1 -0,5 0 0,5 1
#5743
ThomsonreflectómetroHaz de He
n e(cm
-3)
0
2 1012
4 1012
6 1012
8 1012
1 1013
-1 -0.5 0 0.5 1 1.5
#13574
Haz de Li
Haz de HeThomson
n e(cm
-3)
0
2 1012
4 1012
6 1012
8 1012
1 1013
1.2 1013
-1 -0.5 0 0.5 1
#6296
ThomsonreflectómetroHaz He
n e(cm
-3)
0
100
200
300
400
500
600
700
800
-1 -0.5 0 0.5 1
#6296
Haz de HeECEThomson
Te(e
V)
Supersonic He beam diagnostic: Edge profile and Validation of C-R model-a) Comparison with reflectrometry, Li beam and TS--> density profile - b) Comparison with ECE Langmuir probes and TS--> temperture profile-c) Self consistency: reproduction of full emission radial profile
emiss.(nm) 667 706 728
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Removal TechniquesRemoval Techniques
Film scavengers: Complete suppression of C-filmdeposition in technical plasmas by addition of some reactive gases: N2, NH3, CNH, SH2, etc…
Suppression of C deposition in CH4/N2/H2 (10:0-10:80)GD(PPCF 44 (2002) L37)
N2 injection on sub-divertor ASDEX-Up: suppression of Cre-deposition (Nucl. Fusion 45 (2005) L27)
N2 sub-divertor injection tested in JET: Nov. 2006
Film scavengers: Complete suppression of C-filmdeposition in technical plasmas by addition of some reactive gases: N2, NH3, CNH, SH2, etc…
Suppression of C deposition in CH4/N2/H2 (10:0-10:80)GD(PPCF 44 (2002) L37)
N2 injection on sub-divertor ASDEX-Up: suppression of Cre-deposition (Nucl. Fusion 45 (2005) L27)
N2 sub-divertor injection tested in JET: Nov. 2006
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Mechanism of C-film inhibitionMechanism of C-film inhibition
Cryogenic Trap Assisted Mass Spectrometry (CTAMS)Cryogenic Trap Assisted Mass Spectrometry (CTAMS)
0
0.2
0.4
0.6
0.8
1
100 150 200 250
Vapour Pressures at Low T
P CNHP NH3P H2OP C2H2
P v
ap. (
Pa)
T (K)
1-pumping system 7-diaphragm2-B-A manometer 8-mass spectr.3-Cap. Manometer 9-optic port4-cutting valve 10-manipulator5-gas inlet 11-cryogenic trap6-anode 12-float V measure
1-pumping system 7-diaphragm2-B-A manometer 8-mass spectr.3-Cap. Manometer 9-optic port4-cutting valve 10-manipulator5-gas inlet 11-cryogenic trap6-anode 12-float V measure
Vapor pressure vs. T for different species
Vapor pressure vs. T for different species
J.A. Ferreira et al.PFMC-11. Griefswald 200621 IAEA. Chengdu 2006Submitted: J.Vac.Sci.Tech.Chem Vap. Dep.
J.A. Ferreira et al.PFMC-11. Griefswald 200621 IAEA. Chengdu 2006Submitted: J.Vac.Sci.Tech.Chem Vap. Dep.
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
CTAMS resultsCTAMS results
CH4/N2/H2 (10:10:80) plasmaCH4/N2/H2 (10:10:80) plasma
N2/H2 (20:80) plasmaN2/H2 (20:80) plasma
condensationcondensation releaserelease
Main product:acetylene
Main product:acetylene
Main product:HCN
Main product:HCN
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
CTAMS summaryCTAMS summary
Plasma Mixture
Main Products Secondary Products
Characteristic Product Ratios
CH4/N2/H2
10:10:80
Acetylene,
Ethylene,HCN
Acetylene , NH3 C2H2/C2H4=3
HCN/C2=0.1
CH4/Ar/H2
10:10:80
Acetylene, Ethylene Masses 27-29 C2H2/C2H4=1
N2/H2
20:80
HCN ,
Acetylene
C2N2 ,
NH3
HCN/C2H2=4
C2H2/C2H4=1.8
Proposedmechanism:Proposedmechanism:
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
JET experiments JET experiments ( Nov.06)( Nov.06)
Three scenarios:
- SP low Horizontal+ Type I ELMs,GIM 11, Q<1.2 1022 e/s
- SP low Horizontal-sweep + Lmode ,GIM 11, Q< 6.1021 e/s
- SP low Vertical + Type I ELMs,GIM 11 Q<8 1021 e/s
N2N2
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
JET experiments JET experiments ctnd’ctnd’
Nitrogen scavenging 30/10/06 late
0
510
15
20
2530
35
40
6824
1
6824
2
6824
3
6824
4
6824
5
6824
6
6824
7
6824
8
6824
9
6825
0
JET pulse #
nor
mal
ized
n
[Hz/
s]
N2 in
Nitrogen scavenging 31/10/06 early
0123456789
10
6825
1
6825
2
6825
3
6825
4
6825
5
6825
6
6825
7
6825
8
6825
9
JET pulse #n
orm
aliz
ed
n [H
z/s]
H modeH mode L modeL mode
No significant effect seen with SP at low tile 3 either (H mode)No significant effect seen with SP at low tile 3 either (H mode)
Compatibility of toroidal injection with Type I ELM for required N2 fluxes at JET??? try local injection with AUG fluxes(extrapolated)
Compatibility of toroidal injection with Type I ELM for required N2 fluxes at JET??? try local injection with AUG fluxes(extrapolated)
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
Removal of a-C:H in gapsRemoval of a-C:H in gaps
Plasma etching in castellatedstructures (1mm wide x3mm deep)
Plasma etching in castellatedstructures (1mm wide x3mm deep)
Etching ratesDeduced by full annealing (TDS) beforeand after plasma exposure:He/O2(20%): 12 nm/minH2/N2(20%): 3.6 nm/minB/C films: much lower rates
Etching ratesDeduced by full annealing (TDS) beforeand after plasma exposure:He/O2(20%): 12 nm/minH2/N2(20%): 3.6 nm/minB/C films: much lower rates
Similar rates if C-coated elements were facing the bottom of the chamber where only a weak plasma was detected (LP)
Similar rates if C-coated elements were facing the bottom of the chamber where only a weak plasma was detected (LP)
Atomic O, surviving after a few collisions with the walls,is the responsible of cleaning.
Atomic O, surviving after a few collisions with the walls,is the responsible of cleaning.
J.A. Ferreira et al. 12-ICFRM. Sta. Barbara. 2005To appear in J. Nucl. Mater.
J.A. Ferreira et al. 12-ICFRM. Sta. Barbara. 2005To appear in J. Nucl. Mater.
Laboratorio Nacional de FusiónAsociación EURATOM-CIEMAT
C-studies (future-C-studies (future-2007)2007)
CD,CCD,C22, He beam, He beamemission emission (pulsed)(pulsed)
-Chemical sputtering of doped graphite (metal carbides)
(in collaboration C. Garcia-Rosales)
TJ-II NBI Plasma
C dopedC
Methane/He injectionHolder:rotable, radial displacement