InstitutfürPlasmaphysik Assoziation E UR ATO M -Forschungszentrum Jülich U Plasma-Wall Interaction TF – Meeting 13.-15.11.05 – SFA Ljublijana SEWG Chemical Erosion S. Brezinsek InstitutfürPlasmaphysik Assoziation E UR ATO M -Forschungszentrum Jülich U Plasma-Wall Interaction TF – Meeting 13.-15.11.05 – SFA Ljublijana SEWG Chemical Erosion S. Brezinsek Report of the Special Expert Working Group on Chemical Erosion S. Brezinsek TF-E Institut für Plasmaphysik, Forschungszentrum Jülich GmbH, EURATOM Association, Trilateral Euregio Cluster, D-52425 Jülich, Germany SEWG members: CEA E. Tsitrone, E. Delchambre FZJ A. Pospieszczyk, A. Kirschner, A.Kreter, D. Borodin, V. Philipps … IPP W. Jacob, J. Roth, Ch. Hopf, T. Schwarz-Selinger R. Pugno, A. Kallenbach, W. Bohmeyer, M. Baudach … UKAEA M.F. Stamp CIEMAT F. Tabares, D. Tafalla, J.A. Ferreira FOM G. vanRooij, J. Westerhout and TFE members
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EU Plasma-Wall Interaction TF – Meeting 13.-15.11.05 – SFA Ljublijana SEWG Chemical Erosion S. Brezinsek EU Plasma-Wall Interaction TF – Meeting 13.-15.11.05.
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Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Report of the Special Expert Working Groupon Chemical Erosion
SEWG members:CEA E. Tsitrone, E. DelchambreFZJ A. Pospieszczyk, A. Kirschner, A.Kreter, D. Borodin, V. Philipps … IPP W. Jacob, J. Roth, Ch. Hopf, T. Schwarz-Selinger
R. Pugno, A. Kallenbach, W. Bohmeyer, M. Baudach … UKAEA M.F. Stamp CIEMAT F. Tabares, D. Tafalla, J.A. FerreiraFOM G. vanRooij, J. Westerhout and TFE members
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Motivation - ITER
Beryllium
Tungsten
ITER
Lifetime issues Erosion, transport, and deposition of divertor material (CFC) Erosion, transport, and deposition of first wall material (Be) => mixed material systems (Be, C, W) Control of transient heat loads (ELMs and disruptions)
Safety issues Retention of tritium via co-deposition Methods to release the trapped tritium Dust formation (Be and T)
Research goal: minimisation of risksand optimisation of ITER availability!
Issues reflect the principle structure of the special expert working groups! All topics are related to each other!
Graphite
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
ITER – Divertor Plasma Parameter Range
Standard operation scenario Semi-detached and recombining divertor plasma (Te<1.5eV) High ion and atom flux (>3*1024 m-3) High surface temperature (up to1600 K)
-0.2 0.0 0.2 0.4 0.61E17
1E19
1E21
1E23
1E25
ion flux atom flux electron density electron temperature
flu
x [1
/m2 s]
, den
sity
[1/
m3 ]
distance along outer plate [m]
0
5
10
15
20
tem
per
atu
re [
eV]
B2-Eirene simulation for the ITER outer divertor
(A.S. Kukushkin)
Result from AUG with W main chamber and C divertor (Kallenbach et al. 2006) :Outer Divertor is the remaining source of carbon => Chemical erosion main process
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Chemical Erosion Yield - Present Description
Erosion yield Y as function of Surface temperature Incident ion energy Incident particle flux
Roth et al. PSI 2004
ITERrange
1019
1020
1021
1022
1023
1024
10-3
10-2
10-1
Che
mic
al E
rosi
on Y
ield
(at
/ion)
Ion Flux (m-2
s-1)
Ion Beams IPP PSI1 JT-60U outer div ToreS 2001 ToreS 2002 TEXTOR PISCES JET 2001
1025
But in ITER: Detached plasma operation Comparable atom and ion flux Low energy of incident particles Hot target surface
Y =chem
C
D
chem
Fuel outflux:
Hydrocarbon influx:
C
chem
D
Erosion yield:
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Motivation - Tasks
Which species are eroded from the PFC? Methane-, ethane-, propane family ….
Where are the species eroded from? How much is eroded? Spatial distribution of the erosion yield along the target ….
What does the plasma do with the eroded hydrocarbons? Hydrocarbon catabolism and transport….
Where are the break-up products deposited?Inner divertor ….
Amount of deposited particles? Which hydrocarbon films are produced?Hard layers, soft layers….
Which species is re-eroded?Higher hydrocarbons preferred ….
We have to understand:
We should (try to) influence (control) these processes to ensure a safe operation.
Erosion
Migration
Deposition
Re-erosion
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
ITER predictions / SEWG
Predictions for
ITER
Data base & Codes: HYDKIN
ADAS, TRIM…
Code and data base validation: benchmark experiments TEXTOR, AUG, TJ-II …
Plasma backgroundB2-Eirene
or EDGE2D
Tokamak experiments JET, AUG, TEXTOR…
ERO modellingLaboratory experimentsMAJESTIX …
Linear experimentspilot-MAGNUM, PSI-II
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Outline
Recent experimental results from: TEXTOR TJ-II ASDEX Upgrade JET Pilot-MAGNUM PSI-II Laboratory Experiments (IPP) ERO – ITER predictions
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
TEXTOR Photon efficiency calibration: benchmark for HYDKIN and ERO Hydrocarbon catabolism 13CH4 experiments Long term deposition and erosion pattern ….
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Spectroscopic approach
C 2
C D C2 y 2
A-XC D CD2 y
A-X
CD CD4
A-X
~
Photon flux proportional to particle flux (in ionising plasmas)
C2CD C2y2
A-X
CD CD CD4
A-X
Effective inverse photon efficiencies (D/XB-values) include dissociation chain D/XB-values depend on geometry, surface conditions etc.
=B
D
X
: - particle flux
X X - e citation rate coefficient B B - ranching ratio
f t- photon lux [el. ransition] t
D - ecay rate [ionisation, dissociation ...]D
Chemical erosion yield is given by a corrected methane erosion yield
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Comparison with HYDKIN and ERO
calculations:
D/XB values without contamination from deposited and re-eroded hydrocarbons
Simple and highly reproducible plasmas
D/XBExp. =36D/XBHYDKIN=46D/XBERO=32
CD A-X band(CD from CD4)
TEXTOR: Photon Efficiencies for Methane
plasma
gas inletCD A-X430.7+/-1.0nm
CD A-X430.7+/-1.0nm
gas inlet
BB
top view side view
# 98032# 98031 TEXTOR TEXTOR
high field side
ERO modelling CD A-X light
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
CxHy in D plasmas: Te=35 eV, ne=2.2*1018m-3 at the emission locationCxDy in H plasmas: Te=45 eV, ne=1.8*1018m-3 at the emission location
CH A-X band (Gerö band) C2 d-a band (Swan band)
Brezinsek et al. PSI 2006
TEXTOR: Effective Photon Efficiencies for CxHy , CxDy
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
HYDKIN: Photon Efficiencies for Methane
Comparison of measured effective photon efficiencies with HYDKIN (Reaction kinetic analysis - Reiter 2006) for CH from CH4
(const. plasma, no deposition, no transport)
Janev-Reiter database is reliable in the range between 5 eV and 100 eV Influence of other surface parameter and geometry: loss of photons Data base is used as input for the ERO code!
Brezinsek et al.PSI 2006
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
TEXTOR: CD+ Observed in Hot Edge Plasmas
TEXTOR benchmark experiment with CD4: 20 % of theoretically expected
CI 909.5 nm per C observed 50 % of theoretically expected
CII at 426.7 nm per C+ observed 20 % of theoretically expected
D per D observed
l / nm
0.0
0.2
0.4
0.8
420.0 425.0415.0 430.0 435.0inte
nsity
/ ar
b. u
nits
T 3500 Krot»
TEXTOR #93964
CD A-X bandmodelling
CD
=> CD+ identified in TEXTOR plasmas=> break-up via molecular ions important
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Part of the dissociation chain (CH4):
CH4+
CH4
CH3+
CH3 CH2 CH C
CH2+ CH+ C+ C2+
Reaction kinetic analysis with HYDKIN (Reiter 2006) for CH4
Te=45 eV
CH+
CH
Te=5 eV
CH
CH+
Hot limiter plasma (TEXTOR, TJII)Cold divertor plasma (AUG, JET)
HYDKIN: CH+ vs. CH in the CxHy Catabolism
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
TJ-II Hydrocarbon injection experiments a-C:H film production and destruction due to hydrocarbon puffing Nitrogen scavenger experiments ….
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
TJ-II: Hydrocarbon Injection Experiments
Stellarator – current free device; Strong ripple; ECRH heated plasmas Injection of CH4, C2H4 and H2 through a mobile instrumented graphite limiter
Gas pulses of 12-15 ms (4 – 8x1018 particles) Much lower fuelling efficiency for C2H4 than for H2. Hα photon yield 15% per H atom
that of H2 (Garcia-Cortes et al. JNM 2005)
Photon flux ratio CH/Hα 3 times higher for C2H4 than for CH4 (Te=3eV ne=2x1018 m-3) deposition of carbon films with high H content
#12940 (H2 puff)
12940.Densidad2_
H wallTi (0)(a.u.)CV (a.u.)
1000 1050 1100 1150 1200 1250
ne (1012
) (cm-3
)H limiter
0
0.4
0.8
Time (ms)
1000 1050 1100 1150 1200 1250
#12937 (C2H
4 puff)
Time(ms)
0.8
0.4
0
H
CH
Tabares et al.PSI2006
C2H4
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
AUG Photon efficiencies, hydrocarbon particle fluxes and erosion yield in detached and attached plasmas Long term erosion deposition pattern Carbon source determination 13CH4 injection experiments ….
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
z /
m
1.0 1.5 2.0R / m
OSP sweep
injectionintrinsic
-1.25
-0.75
-0.50
S4=1.594 m
T4
S3
NP
S4
S2=0.541 mS3=1.038 m
S1=0.000 m
S1
T1LP9
ISP sweep
injection intrinsic
-1.00
T3=1.170 mT4=1.242 m
valve
S2
T3
LP1NP: Neutral Pressure GaugeLP: Langmuir Probe
VOL
T1=0.395 m
VOLT3
ROV18
ROV16
ROV15 (blind)
ROV14
ROV13
ROV12
ROV11
T4
ROV17
AUG: Hydrocarbon Injection in Detached Plasmas
L-mode discharges with outer divertor detachment Injection of CH4 and C2H4 in the SOL, Separatrix and PFR
in the volume: Te=1.2 eV, ne=3*1020m-3 at the target (separatrix): Te=2.3 eV, ne=4*1018m-3
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Brezinsek et al. PFCM 2006
AUG: Photon Efficiencies in Detached Plasmas
Intrinsic CD A-X spectrum --- attached plasma ---
Intrinsic CD A-X spectrumwith strong BD contamination
--- detached plasma ---
CH A-X spectrum from injection and CD A-X intrinsic background
--- detached plasma ---
CH A-X spectrum from injection and CD A-X intrinsic background
--- attached plasma ---
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Brezinsek et al. PFCM 2006
AUG: Photon Efficiencies in Detached Plasmas
Intrinsic C2 d-a spectrum --- attached plasma ---
Intrinsic C2 d-a spectrum --- detached plasma ---
C2 d-a spectrum from injection --- detached plasma ---
C2 d-a spectrum from injection --- attached plasma ---
Below the detection limit!
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
AUG: Erosion Yields in Detached Plasmas
Decrease of CH and C2 light much stronger than increase of D/XB
=> Significant decrease of the hydrocarbon flux in detachment
D/XB for CH from CH4: 18 +/-7D/XB for CH from C2H4: 47 +/-19
Measured D/XB values are slightly higher than in attached plasmas and higherthan predictions with HYDKIN!
Ychem=3.2*10-2 (ion flux only)
Ychem=2.9*10-3 (atom and ion flux)
Erosion yield at the separatrix for detached conditions:
Reduced influx is largely compensated by lower plasma ion outflux=> atom outflux important
Roth-formula: Ychem=2.5*10-3 (atom and ion flux)
only ions
ions & atoms
detachment (at separatrix)
Roth et al. NF 2004
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
JET Hydrocarbon injection experiments a-C:H film production and destruction as function of the strike-point Nitrogen scavenger experiments 13CH4 tracer experiment….
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
2.20 2.40 2.60 2.80 3.00 3.202.20 2.40
7
6
53
1
2
4
#63253
t2
t3
t1
KS3I KS3O
1.80
1.70
1.60
1.50
1.40
1.30
1.80
1.70
1.60
1.50
1.40
1.30
he
ight
[m
]
major radius [m]
GIM 10OSP sweep
#63250
KS3 - integrated photon fluxes
loc
al T [e
V]
e
time [s]22 23 24 25
021
4
5
12
20
loc
al n
[1
0 m
]e
19-3
n mapped on GIM10 location
e
T mapped on GIM10 location
e
1
0
4
8
PFREFIT
#63250
KY4D #63253
2
3
16
24
SOL
Circumferential injectioninto the attached outer divertor:i) Discharge with C2H4 injectionii) Discharge with H2 injection
Nearly identical local plasma conditions
Assumption: symmetric and homogenous injection
JET: CxHy Contribution to the Erosion Yield
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Most reliable value for Ychem is achieved when the strike point is at GIM10
Toroidal inhomogeneity of gas injection module included (=> information from 13CH4 tracer experiments)
Bypass in the outer divertor considered!
Photon efficiencies and erosion yield lowered in comparison to first analysis (Brezinsek et al. EPS 2005)
D/XB for C2 Swan band from C2H4 about 75 Ychem associated to higher hydrocarbons about 0.6%
SOL
sweep
#63253KS3O
0.25
0.50
0.75
1.00
1.25
1.50
1.75
PFRsweep
YC
2Hy [
%]
impinging ion flux (at GIM10) [10 ions s m ]23 -1 -2
chem
KY4D
EFIT
0.4 0.8 1.2 1.60.0
Brezinsek et al. PSI 2006
JET: CxHy Contribution to the Erosion Yield
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
JET: Preferred Release of Hydrogen-rich Hydrocarbons
Ratio of C2/CH line emission indicate hydrogen-rich layer near to louvre Strike-point utilised to “clean up” deposited areas Thermal decomposition of deposited layers most probable
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
JET: History Effect
0
20
40
60
80
100
120
140
68
13
3
68
13
4
68
13
5
68
13
6
68
13
7
68
13
8
68
13
9
68
14
0
68
14
1
68
14
2
68
14
3
68
14
4
68
14
5
68
14
6
68
14
7
68
14
8JET pulse #
no
rma
lize
d
[
Hz/
s]
H mode cleaningsweep
L modereference sweep
H modehorizontal target
H mode verticaltarget
Identical discharges!
doubleNBI
Material deposition on the QMB depends on the strike-point position of previous discharges! Identical plasma discharges lead to different net deposition on QMB Strike-point configuration as well as ELM type influence deposition
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Pilot-MAGNUM Erosion yield at ITER-relevant fluxes….
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Pilot-MAGNUM: Plasma Parameter Range
Arc
Coils
ThomsonScattering
Target
Spectroscopy
0.55 m
Parameter variation:Source current & flowVessel pressureMagnetic fieldTarget potential
5
4
3
2
1
0
Ele
ctro
n T
empe
ratu
re (
eV)
1019
2 3 4 5 6
1020
2 3 4 5 6
1021
2 3 4 5 6
1022
Electron Density (m-3
)
>1023 H+/m2s >1024 H+/m2s >1025 H+/m2s
Ion fluxes and plasma parameters at the target are comparable to predicted ITER divertor conditions!
v. Rooij et al.ITPA Toronto 2006
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Pilot-Magnum: First Results on Erosion Yields
Ionising hydrogen plasma (Te=3.5 eV)in front of the fine grain graphite target.
Preliminary work basedon CH A-X band analysis: gas injection for calibration in preparation uncertainties in the surface temperature
New experiments planed!
Experimental data in-line with the Roth-formula!
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
PSI-II Re-erosion of hydrocarbons at elevated wall temperatures Hydrocarbon spectroscopy….
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
TMPQMS analyses the
exhaust ~1 m upstream
forepump
Large collector probe
duct
Langmuir probe
100 sccm H2
discharge regiontarget chamber
0.1 Pa
TM pumps
20 cm
floating W disk
CH4 +100 sccm H2
~200C~ 150C
0.8 Pa
PSI-II: CxHy Erosion from Deposited a-C:H Layers
Bohmeyer et al. PFCM 2006
• Injection of methane into a PSI-II hydrogen plasmas• a-C:H layers build up on the “heatable” wall• Erosion by neutral hydrogen• Detection of the eroded species with the aid of QMS and collector probes in the pump duct
Collectorprobes for
in situ analysis
heated
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
4000 5000 6000 7000 8000tim e (sec)
0E+0
2E-12
4E-12
6E-12
8E-12
inte
nsity
(A
)
2 6
1 5
2 7
2 9
plasm aO N
2 sccm C H 4
Increasing wall temperature
Wall temperature fixed at 180° C
Dominant erosionproduct from
the hot wall (180°C)is acetylen (m=26)!
PSI-II: CxHy Erosion from a-C:H Layers at Walls
QMS in the pump duct:
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
EU Plasma-Wall Interaction TF – Meeting13.-15.11.05 – SFA Ljublijana
SEWG Chemical ErosionS. Brezinsek
PSI-II: Deposition/Erosion in the PSI-II Pump Duct