Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 1

EU-PWI Task Force &

EFDA Plasma Edge Technology Programme

Alberto Loarte, Joachim Roth, Volker Philipps

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 2

Outline

1. Background to EFDA Plasma Edge Technology Programme and Integration with EU-PWI Task Force

2. Description of Existing Tasks & Status Details to be found in http://efdasql.ipp.mpg.de/efdatpp

3. Plans for new Tasks in 2006

4. Discussion of Priorities for 2007 (ELE or post-ELE EFDA ?)

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 3

Background

Need of fundamental Understanding of PWI Processes

Well defined Laboratory Experiments

Specific Modelling and Extrapolation to ITER

Contributions from Associations without voluntary Physics Programme

Financial Volume (2005): 1 M€ (20% sub.) 5.1.a, 250 k€ (40% sub.) 5.1b

(0.8 M€ in 5.1.a, 250 k€ in 5.1b for 2006)

EU Task Force aims to better integrate Technology and Physics Aspects of the EFDA Plasma Edge Technology Programme

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 4

Integration with EU-PWI TF Topics (I)

Tasks in 2002/2003/2004/2005

1. Erosion behaviour

Chemical Erosion of C by D/Be, TW2-TPP-ERDEP (√) (EU-US)

Sputtering of W and Be, TW3-TPP-ERTUBE (~ 60% √) SEWG

Chemical Erosion of C, TW4-TPP-ERCAR (~ 80% √) SEWG

C/W/Be mixed-material formation, TW5-TPP-CARWBER (EU-US)

2. Material transport and re-deposition

Flake Formation from Deposits, TW2-TVM-CFC2 (√)

Scavenger Technique, TW3-TPP-SCAVOP (√) SEWG

CxHy Formation and Re-deposition in ITER Geometries, TW4-TPP-TRIDEP

Erosion/deposition metal wall + C divertor TW5-TPP-TILCAR

Midplane and Divertor W macro-brush studies in ASDEX-Upgrade

UT4-TUNAUG & UT5-MBWAUG

(√) Already reported at last year‘s meeting (√) Reported this year

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 5

Integration with EU-PWI TF Topics (II)

3. Fuel recycling, retention and removal (2 SEWGs)

Optimisation of He-O Glow for C-H removal, TW5-TPP-HEGLO

Characterisation PFC Oxidation Damage, TW5-TPP-TILCAR

T removal by non-O2 oxidative methods, TW4-TPP-TRIREMA-B

T retention in ITER-like material mixes and Tsurf, TW5-TPP-RETMIX

4. Off-normal heat loads (SEWG)

Modelling of Disruptions and ELMs, TW3-TPP-DISELM (√)

Validation of ELM Damage Modelling, TW3-MATDAM (~ 30% √) (EU-RF)

ELM-Disruption exposed Target Characterisation, TW4-TARCAR (~ 40% √)

W and CFC damage and plasma evolution in ITER, TW5-TPP-ITERTRAN

Modelling of Be damage under Disruptions/ELMs, TW5-TPP-BEDAM (fut.EU-RF)

W and CFC under-threshold damage studies, TW5-TPP-REPELM

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 6

Integration with EU-PWI TF Topics (III)

5. Edge modelling, erosion and deposition modelling

Improvements to ERO Code and ITER Modelling, TW3-TPP-ERMOD (√)

MD Modelling of Erosion Processes, TW4-TPP-CARWMOD (√)

W Erosion and Edge Plasma Contamination in ITER, TW5-TPP-TUNMOD

6. Edge and SOL physics

Improvements to B2-Eirene for ITER Modelling, TW3-TPP-NEUTMOD (√)

Modelling of n-n and n- effects in ITER divertor, TW5-TPP-ITERNEUT

7. Task force relevant diagnostics

Speckle Interferometry for Erosion, TW0-T438/01 (√)

Laser Ablation Techniques for Film Deposition, TW3-TPP-ERDIAG (√)

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 7

Description of Tasks and Status (I)

ERTUBE: High Tsurf erosion of metals (IPP + PISCES-B under EU-US collaboration)

R. Doerner + K. Schmid + J. Roth

A u

High Tsurf erosion of metals is a general property for low and high Z metals that

requires Tsurf > 0.8 Tmelt & Fluxes > 1022 m-2 s-1 & low particle incident energies

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 8

Description of Tasks and Status (II)

ERTUBE: Composition of redeposits in Be C experiments in PISCES-B (IPP + PISCES-B under EU-US collaboration)

Many samples analysed exposed to a range of experimental conditions to determine surface layer structure and composition

PSI 2004, M.Baldwin, et al.

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 9

Description of Tasks and Status (III)

ERCAR: Synergistic effects of C erosion with impurity ions (IPP)Enhanced chemical sputtering by noble gas impurity atoms is confirmed for He, Ne, Ar

ion

~ 180 (Ar), 30 (Ne)

Enhancement of chemical erosion decreases slightly with atomic mass at low impact energies

ITER conditions: Yphys(Ar, Ne) = 0, Y(Ar|D) ~ 0.6,Y(Ne|D) ~ 0.4, RAr ~ 1000, RNe~ 100

C(ion|D)/C(D) = YC(ion|D)/(Ychem/Rion) 0.06 (Ar) 0.4 (Ne) Small effect if Ychem ~ 1%(in agreement with CARWMOD results)

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 10

Description of Tasks and Status (IV)

SCAVOP : Determination scavenger effect dependence on conditions (IPP)Decrease of deposition with N2 reproduced but scavenger effect ?

Clear formation of volatile molecules (HCN),

but also CH3 and NH3 increase with N2

& enhanced N2+ sputtering of a-C:H layers

C2H2 (C2H large source of deposits in the

experiments) decreases dramatically with N2

is this the dominant effect ?

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 11

Description of Tasks and Status (V)

MATDAM + TARCAR: Targets were characterised by FZJ in February and arrived at

TRINITI at the end of July (modelling by FZK, analysis FZJ + ENEA-CNR+Frascati)

m)

m)

(x 10-2 MJ/m2)

Experiments have started already with the

plasma gun calibration and low power

exposure experiments (~ 0.5 MJ/m2, 500 s)

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 12

Description of Tasks and Status (VI)

CARWMOD : MD modelling of W plasma-wall interactions (FZK, TEKES)

Emphasis of W compound effects and W blistering

FZK Studies of W-O system under D flux

TEKES Studies of W-C system under D flux

TEKES W blistering under D and He flux

Example Result He (@ Einc = 50/100 eV) on W forms bubbles that escape W without

causing blister

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 13

Description of Tasks and Status (VII)

NEUTMOD : n-n effects are not negligible in ITER B2-Eirene has been upgraded to handle these effects (including MAR) (FZJ)

for same q pk P DT goes up with n-n col.

for same pumped DT S DT goes down (colder gas with n-n

col.)

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 14

Description of Tasks and Status (VIII)

TW0-T438-01 : Erosion diagnostic with speckle interferometry (CEA) Technique tested in ideal “realistic” conditions produces an ideal resolution of ~10 m 3 method can resolve depths from 2000 m to 50 m with a 10 m resolution Implementation in tokamak requires addressing vibration + large observation area

further tests in CEA and (if successful) in Tore-Supra will be pursued

Proposed tokamak diagnostic set-up

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 15

Description of Tasks and Status (IX)

ERDIAG-a : Diagnosis of retention by laser desorption Technique tested in lab conditions with well characterised films Technique demonstrated in TEXTOR with non-optimum laser with good results Diagnostic design for JET approved aiming at demonstration in divertor plasmas

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 16

Description of Tasks and Status (X)

ERDIAG-b : Diagnosis of retention by LA-OES (or LIBS)Laser Ablation Optical Emission Spectroscopy (CEA)

Technique tested in lab conditions with well characterised films Technique demonstrated on TEXTOR tiles Diagnostic incorporated in plans for JET laser ablation system for de-tritiation

D/C TEXTOR tile front

D/C TEXTOR tile back

The critical issue is to optimise crater (depth + profile) to guarantee relevant desorption

(by strata)

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 17

Plans for new Tasks in 2006

Mixed Materials Studies Study of W/C/O deposits from tokamaks (ASDEX Upgrade, TEXTOR, etc.) with focus on mixed-material formation and T retention Modelling of mixed-material formation processes and T retention

Study of W-C-H (+O) system

Study of the Be-C-D (+O) system Proof of principle for erosion deposition in-situ diagnostic

Ideas ? Demonstration of T-removal techniques for mixed-materials

Ideas ? Experimental studies of dynamics of molten layers under transient loads in tokamaks

Ideas ? Dedicated ITER PWI modelling ?

Ideas ?

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 18

Money matters : History and Facts

2003 2004 2005 20060

500

1000

1500

2000

Oficial Budget Real Budget

Year

Art

icle

5.1

.a (

kEu

ros

@ 2

0%

sub

sidy

)

EFDA Plasma Edge Technology Programme Budget

0

100

200

300

400

500

600 Article

5.1.b

(kEu

ros @ 40

% subsidy)

Budget allocated for TPP area of EFDA Technology programme roughly constant since 2003

(20% reduction in 2006 EFDA Technology € due to start of ITER construction)Real requested/allocated budget increases with time

(in 2005 hopefully by 80-90%)

Increase of requested/allocated budget reflects interest of EFDA management on PWI issues + the good work of EU-PWI Task Force!!

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 19

Priorities for 2007

Experiments/Modelling on erosion/redeposition in lab

experiments and fusion devices

Mixed Materials Studies T retention and removal

Diagnostics for in-situ T retention measurement

Diagnostics for in-situ erosion/redeposition measurements

Dedicated PWI modelling in ITER

(erosion/redeposition in main QDT=10 scenario + ramp-up phase)

Studies of Be damage under ELMs and disruptions

More ideas are very welcome !!!!!

Alberto Loarte EU Plasma-Wall Interaction Task Force Meeting – CEA – Cadarache 17 – 10– 2005 20

Conclusions

EFDA TPP Technology Programme is well integrated with EU-PWI Research Programme and producing ITER-relevant results

As recognised by EFDA and ITER management

Two major EFDA Collaborations with US (PISCES-B) and RF (TRINITI) on-going New large collaboration about to be approved with RF (Kurchatov +

TRINITI) on Be damage under ITER transient loads EU staff to collaborate in-situ in the experiments (Euratom Mobility) + EU

industry to provide targets (+ few Be coated targets?) + destructive analysis of targets to be done in EU labs (new EFDA tasks in 2007)

Many Associations involved : CEA , CIEMAT ,

ENEA-Frascati , ENEA-CNR Milano , FOM-NRG ,

FZJ , FZK , IPP , IST , ÖAW ,

TEKES , and VR

How to get “new” Associations involved in Technology Programme ?