1Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TEC
Hydrocarbon spectroscopy on EU tokamaks
S. Brezinsek on behalf of the EU task forcefor Plasma-Wall Interaction
presented by V. Phillips
TEXTOR: Photon efficiencies for different types of hydrocarbons in ionising plasmas
HYDKIN: Measured and calculated photon efficiencies in different devices
AUG: Chemical erosion and photon efficiencies under detached plasma conditions
JET: Chemical erosion yielded in higher hydrocarbons
TF-E
2Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TECTEXTOR– Photon Efficiencies for Hydrocarbons: CD4
Aim: Measure D/XB values without contamination from deposited and re-eroded hydrocarbons.
Comparison with HYDKIN and ERO calculations
D/XBExp. =36D/XBHYDKIN=46D/XBERO=32
CD A-X band(CD from CD4)
3Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TEC
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
4Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TECTEXTOR: 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
Dper H 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
5Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TEC
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
HYDKIN: CH+ vs. CH in the Hydrocarbon chain
Te=5 eV
CH
CH+
Hot limiter plasma (TEXTOR)Cold divertor plasma (AUG, JET)
6Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TECHYDKIN: Effective Photon Efficiencies for Methane
Comparison of measured effective photon efficiencies with HYDKIN calculations (const. plasma, no deposition, no transport)
• Janev-Reiter database is reliable in the range between 5 eV and 100 eV• Detailed comparison with the aid of erosion and deposition models necessary
Brezinsek et al. PSI 2006
7Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TECz
/ 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
8Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TEC
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 ---
9Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TECAUG: 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 +/-19D/XB for C2 fromC2H4: 407 +/-134
Measured D/XB values are 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 outflux. => Consideration of neutral outflux to the target is important!
Erosion yield in line with Roth-formula: Ychem=2.5*10-3 (atom and ion flux)
10Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TEC
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
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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
Brezinsek et al. EPS 2005
JET: CxHy Contribution to the Erosion Yield
11Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TECJET: CxHy Contribution to the Erosion Yield
• Most reliable value for Ychem is achieved when the strike point is at GIM10
• Toroidal inhomogeneity of gas injection module included (=> information from tracer experiments)
• Bypass in the outer divertor considered!
Photon efficiencies and erosion yield lowered in comparison to first analysis (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
12Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich
ITPA - DSOL - Toronto S. Brezinsek
TECSummary
TEXTOR:- Photon efficiencies for different hydrocarbons- Information about hydrocarbon catabolism- Detection of CH+ in the hot edge plasma
AUG:- Photon efficiencies for CH in detached plasma conditions - Hydrocarbon particle flux reduction in detached plasmas- Neutral flux to the target important for yield determination
JET:- Circumferential injection in the outer divertor - Erosion which yielded in C2Hy lower than previously deduced
HYDKIN:- Janev & Reiter data base reliable for ionising conditions- Normalised D/XB values deduced in different machines and compared with HYDKIN