Prsentation PowerPoint

1
Plasma Wall Interactions Tore Supra recent
results
E. Tsitrone for Tore Supra team With special
thanks to M. Bécoulet, N. Bernier, S. Bremond,
C. Brosset, J. Bucalossi, L. Colas, Y. Corre, X.
Courtois, P. Dore, A. Ekedhal, E. Gauthier, P.
Ghendrih, C. Grisolia, A. Grosman, J. Gunn, J.
Hogan, T. Loarer, C. Martin, P. Monier Garbet, R.
Mitteau, B. Pégourié, M. Richou, P. Roubin, P.
Tamain

• Not mentionned
• Disruption mitigation (SEWG transient heat
  loads)
• Laser cleaning (SEWG T removal)
• Dust (SEWG dust)
• C erosion modelling phys self sputtering
• ergodic coils for ELMs suppression design for
  ITER modelling for DIIID experiments

• Outline
• TS experimental program
• Power exhaust
• Fuel retention
• Diagnostics for PWI
• Lock in thermography
• Speckle interferometry
• Prospects for 2007

2
TS experimental program Power exhaust
3
2006 High power operation
Design integrated scenario for routine high power
long pulse (CIMES) ? combined RF heating (10 MW,
30 s)
Main limitation from PWI Density control ok,
power exhaust on TPL ok Local overheating of RF
antennaes power limited by IR safety system
4
Localized fast particles impact

LHCD launcher
ICRH antenna
ICRH 1) Fast ions (total PICRH), 2 ) Sheath
effect (local PICRH) LH 3) Fast e- local
(near field local PLH) or on other PFCs (total
PLH) 4) Arcing (local PLH)
Combined RF heating careful optimisation
(radial position of antennaes)
5
Start up limiter studies for ITER
Aim confirm ITER design assumptions on SOL
profiles during ramp up (transient steady state
?)
6
Transient profiles steady state
Transient SOL profiles steady state Different
decay lengths LCFS and far SOL, density plateau
Model for frad benchmarked
7
TS experimental program Fuel retention
8
Extend retention database to lower Te
Impurity seeded long pulse with double feedback
ne on D2 injection, frad on Ne injection (up to
80 )

• High Zeff 30-60 of injected e- provided by
  Ne, BUT 4-12 Ne/D

• Continuous Ne injection Ne mostly pumped by TPL

• Modest effect on Te
• 10 eV decrease at LCFS (down to 30-40 eV, but
  80-100 eV in GJA)

9
Particle balance ongoing analysis
All Ne pumped by TPL

• Possible interpretation
• Bulk diffusion
• Plugging of pores by Ne ?
• Other impurities Ar, N2
• Effect of low D2 injection for equilibrium with
  wall ?
• Repeat experiment at same D2 flux
• Codeposition
• Influence of Ne on C erosion/redep (CII light
  decreased with Ne, CII/Da increased Ne
  sputtering)
• Other impurities Ar, N2

Decrease of retention rate by factor 6,
retention fraction by factor 1.5
10
TS deposited layers multiscale porosity
Porosity (volumetric adsorption) Micropores (d
1 nm) 10 Mesopores (d 10 nm) 4
Macropores (d 100 nm)
C. Martin et al.
11
D bonding in C EELS analysis
N. Bernier et al.
no loss of sp2 in CFC ? no sign of chemically
bonded D
FIB lamella
TS samples after high fluence exposure
12
PWI diagnostics
13
Lock in thermography PFC check up
14
Lock in tile evolution on TPL
High Resolution IR camera
High Flux area
Tiles with longer time constant
Depositarea
Flakes
High Flux area
Good correlation Lock-in lt-gt IR Data
Phase-shift cartography
Suspicious tiles
Depositarea
Flakes
15
Speckle interferometry for erosion / redeposition

• Issues addressed in lab
• Resolution (10 mm)
• Vibrations ( iterative methods)
• Large surface observation (divergent beam)
• Large distance ( 2 m)
• Real PFCs shape imaging (TPL ITER divertor
  mock up)
• Still to do
• Reference needed
• Integrated tokamak demonstration

16
Prospects
17
Plans for 2007

• New in TS in 2007
• Turbulence probes 3D transport/turbulence code
  ( fast camera)
• ITER like ICRH antenna
• Articulated inspection arm

• C migration / D retention
• Chemical erosion ? Collaboration with Textor
  spectroscopy group
• Expand retention database at lower Te

18
(No Transcript)
19
Annex
20
Ergodic coils for ELMs control

• Coils design for ITER 2 options under analysis

In-vessel coils on blanket modules Small Icoil
Small central perturbations - Difficulties
access,insulation,cooling
External coils -Larger Icoil(x 30) -Larger
central perturbations (x 2) Easy access, can be
supra

• Modelling of ELMs suppression in DIIID (non
  linear MHD code Jorek)

21
Hot spots on LHCD launcher effect of ICRH
Grill C2
Grill C2
TS 38073
?
?
?
?
?
?
?
?
t12s
t19s

• LHCD launcher C2 alone similar hot spot
  evolution on 4 waveguide rows.
• Add ICRH power from antenna magnetically
  connected different hot spot evolution.
• gt Poloidal density asymmetry created by ICRH,
  which is dependent on magnetic
• connections. LH coupling also modified
  during ICRH.

22
(No Transcript)
23
Plasma ramp up at q cst

• Edge diagnostics
• reciprocating LP
• IR thermography
• Aim
• Compare power decay
• lengths measured on TS to
• that used for ITER modelling

Ip feedback controlled for qy4.6
Minor radius ramped 0.42m?0.65m
24
1 limiter, limiter to wall gap 0.12m

• Two radial regions are observed
• Short decay length
• Density plateau superimposed structures

25
Transient / steady-state SOL profiles are very
similar
26
Density regimes for constant qy4.6
Model from O. Zolotukhin, et al., EPS 2006
27
Ergodic coils for ELMs control

• Coils design for ITER 2 options

In-vessel coils on blanket modules Small Icoil
(25kA for q953-5) Small central
perturbations(dbr10-4) - Difficulties
access,insulation,cooling
External coils -Larger Icoil(750-900 kA for
q953-5) -Larger central perturbations
(dbr2.10-4) Easy access, can be supra

• Modelling of ELMs suppression in DIIID (non
  linear MHD code Jorek)

28
Particle balance (preliminary)
Pure D2
Ne frad 60
Ne frad 80
Decrease of retention rate with increasing Ne
injection
NB Ne not taken into acount in particle balance
here
29
Particle balance (preliminary)
Pure D2
D2 pur Inj D2 55 Pam3 TPL 28.5 Pam3 Wall
26.5 Pam3
Ne frad 60
Ne frad 80
Frad 60 Inj D2 45 Pam3 TPL 27.5
Pam3 Wall 17.5 Pam3 Inj Ne 1.6 Pam3 Wall
19.1 Pam3
Frad 80 Inj D2 22 Pam3 TPL 20 Pam3 Wall
2 Pam3 Inj Ne 2.1 Pam3 Wall 4.1 Pam3
30
Particle balance with and w/o Ne
No Ne pumped by TPL
All Ne pumped by TPL lower pumping speed
31
Visible spectroscopy of CII line emission
? Upper bound of integrated carbon source over 3
experimental campaigns




E. Dufour, J. Hogan
32

• Sputtering of carbon
• Experiments well described by physical self
  sputtering
• Including tile gap effects enhances chemical
  sputtering rates by factor 5 to 6, but still
  negligible contribution to overall sputtering
• (Regions of locally higher temperature are seen
  in IR maps of the CIEL surface (deposited
  material in intra-tile gaps?))
• Using this measured locally enhanced surface
  temperature for the chemical sputtering rates,
  these are found to be enhanced by 5x - 6x.

33
Contrôle Frad avec injection Ne
Ne, frad 80 , Zeff 5 D2 22 Pam3, Ne 2.5
Pam3
Ne, frad 60 , Zeff 4 D2 45 Pam3, Ne 1.6
Pam3
D2 pur, nl 5, Zeff 2.2 D2 58 Pam3
D2 pur, nl 4, Zeff 2.8 D2 55 Pam3
34
Bilan particules avec le Ne
35
Flux de particules injectés
D2 pur, nl 4, Zeff 2.8 D2 55 Pam3
Ne, frad 60 , Zeff 4 D2 45 Pam3, Ne 1.6
Pam3
Ne, frad 80 , Zeff 5 D2 22 Pam3, Ne 2.5
Pam3
36
Voie en cours détude
Caractériser la couche amorphe et comparer à des
couches de laboratoire
NRA concentration en D 35 at. EELS C
hybridé sp2 72
D 35 C sp2 47 C sp3 18
W. Jacob, Thin Solid Films, 1998
37
Description des techniques employées
Préparation des lames FIB
Epaisseur 100 nm
38
Caractérisation de la structure du CFC-N11
Lame FIB du CFC irradié
39
D in macroporosity of CFC-N11
b)
Platinium migration on virgin CFC
100 nm
100 nm
1 mm
macropore 100 nm large between matrix
fiber
D tail in CFC macropores relationship to D
trapping deposits ?
40
TS deposited layers multiscale porosity
2 nm
50 nm
micropores
mésopores
macropores

• A- molécule isolée
• B- micropores
• C- monocouche
• D- mésopores

41
Multiscale porosity
Volumetric adsorption
CH4 adsorption, isotherm 77 K
1g C sphere math, r 5 mm, S3.10-4 m2 mono-layer
surface deposit 120 m2/g ? C/D 3 CFC
2 m2/g
Coverage
Porosity micro 10 meso 4
Mesopore 2 nm lt d lt 50 nm
42
Macropores

• Foil 15 µm x 5 µm x 100 nm

Ovoid axis
mesopore Parallel network slit-shaped pores
Macropores (d gt 50 nm) 45 from ovoid axis
Granules spherical particles 20-50
nm homogeneous growth
10 ?mm
43
D retention for high fluence CFC exposure in Tore
Supra
Sample holder and plasma irradiation device
Ionic fluences on the samples
A1 or B1
A5 or B5
J. P. Gunn, L. Begrambekov, C. Brosset et al. J.
Nucl. Mater. 337-339 (2005) 644
44
CFC samples exposed to high fluence in TS
NRA (IPP Garching)
3.7 mm
45
D depth profile and D retention in Sepcarb N11
NRA depth profile measurement V. Kh. Alimov, J.
Roth, C. Brosset (ITPA DSOL-18 task)
46
Lock-In Thermography of Tore Supra TPL
Aim evaluate the heat transfer capabilities of
TPL Tiles, mainly the armour/heat sink bond,
and follow its evolution Principle
sinusoidal photo-thermal excitation on the
component -gt analysis of the
thermal response phase-shift magnitude
IR camera Halogen lamps Supporting
device TPL
Magnitude and phase-shift of surface temperature
vary according to thermal properties and presence
of flaw in the component. Phase-shift is less
sensitive to flux homogeneity and surface
emissivity
47
Speckle interferometry for Erosion /redeposition
Caméra CCD

• Interféromètre de MICHELSON
• Ii I0 (1 V Cos(? ?i))

?i
Laser
Séparatrice
paramètre intéressant phase ?(x,y) différence
de chemin optique entre les deux bras de
linterféromètre ? forme de la surface observée
Miroir Piézoélectrique
z
Surface Observée
?
48
Mesure dérosion par Interférométrie Speckle
Image de phase ?1562,000 nm ?2562,800 nm ?400µm

• Objectif Développer une méthode expérimentale
  pour mesurer lérosion
• Matériaux observés
• Tungstène
• CFC codéposé (PPI)

49
Interférométrie de speckle
I Principe de la mesure
Caméra CCD

• Interféromètre de MICHELSON
• Ii I0 (1 V Cos(? ?i))

?i
Laser
Séparatrice
paramètre intéressant phase ?(x,y) différence
de chemin optique entre les deux bras de
linterféromètre ? forme de la surface observée
Miroir Piézoélectrique
z
Surface Observée
?
50
Procédure de mesure dÉrosion/Redéposition
II Érosion/Redéposition
État de la surface AVANT
État de la surface APRES
DECHARGE PLASMA
51
Mesure dérosion par Interférométrie Speckle
Image de phase ?1562,000 nm ?2562,800 nm ?400µm

• Objectif Développer une méthode expérimentale
  pour mesurer lérosion
• Matériaux observés
• Tungstène
• CFC codéposé (PPI)

52
Procédure de mesure dÉrosion/Redéposition
II Érosion/Redéposition
État de la surface AVANT
État de la surface APRES
DECHARGE PLASMA
53
Speckle on real PFCs
TS toroidal pump limiter
2 cm
TPL picture
Phase imaging ?800 µm
54
Les difficultés de la mesure sur un tokamak
III Conditions Tokamak (1/2)

• Grande distance dobservation entre la caméra et
  la surface (gt 3 m)
• 3 m sur Tore Supra et certainement plus
  sur ITER
• Grandes surfaces des composants face au plasma
  ( 50 x 50 cm2)
• Utilisation de faisceaux déclairage
  divergent ? non uniformité de la sensibilité de
  mesure dans le champ dobservation.
• Présence des vibrations sur les composants
• Méthode expérimentale (vibromètre) et
  numérique (itérative) ? calcul de limage de
  phase en tenant compte des vibrations de la
  surface observée
• Déplacements (x,y,z) de la surface entre deux
  séries de mesure
• Nécessité dune surface de référence
  daltitude pour
• Bilan correct de matière érodée/redéposée
• Décorrélation entre déplacement et
  érosion/redéposition