r. neu: sewg meeting, july 7-8, 2009 1 the eu plasma wall interaction task force : work programme...

R. Neu: SEWG meeting, July 7-8, 2009 1

The EU Plasma Wall Interaction Task Force :Work Programme 2010(-2011)

R. Neu (Deputy TF leader, IPP Garching)E. Tsitrone (TF leader, CEA Cadarache)

With contributions from : S. Brezinsek (FZJ), P. Coad (UKAEA), C. Grisolia (CEA),

T. Loarer (CEA), K. Krieger (IPP), M. Lehnen (FZJ), G. Maddaluno (ENEA), V. Philipps (FZJ), J. Roth (IPP),

M. Rubel (VR)

EFDA contact: R. Zagorski (EFDA CSU Garching)


Outline

1) Introduction: the PWI TF and the ITER context

3) Summary

2) Work programme 2010-2011 : major milestones


Introduction : the EU PWI TF and ITER

context


ITER high priority research needs :strongly PWI related

[D. Campbell, ITPA CC meeting June 2008]

1. Disruption/ Runaway Mitigation1. Disruption/ Runaway Mitigation

2. ELM Control/ Mitigation2. ELM Control/ Mitigation

3. Plasma Facing Materials3. Plasma Facing MaterialsPhysics basis for ITER reference scenarios with W/ Be PFCs ; C removal

4. Scenario Development4. Scenario Development

5. Diagnostics5. DiagnosticsDust / Hot dust ; divertor erosion ; mirrors ; H/D/T inventory

Beryllium

Tungsten

Carbon

Heat loads, runaway electrons: reduction > 1 order of magnitude

reduction > 1 order of magnitude

Radiation cooling, supression of accumulation







Fuel retention

Fuel retention Fuel Removal

Transient heat loads

ELMs and disruptions

Material erosion and transport in tokamaks

Materials

Material migration

High-Z Materials

ITER-like Material Mix

Dust in fusion devices

Dust

EU-PWI TF : targeted at ITER through 7 SEWGs

Material Erosion W R&D

Fuel retention

Dust

Heat loads

ITPA Div SOL : 5 topics

4. Scenario Development4. Scenario DevelopmentRad. cool., accumulation supr.


Task Force Plasma-Wall InteractionMain orientations at

Annual General MeetingContact Persons from 23 associations+ JET TF E and FT, EFDA, F4E, ITER IO

ITPA divertor and SOL (co-chair)

Special Expert Working GroupsAnnual specialised meeting of SEWG members

Joint meetings (Material Mixing & Migration for 2009)

EU PWI TF: mature organisation

Associations Baseline work programme : 20 % (?)Priority support : up to 40 %

EFDA

ITM-TFTG MHDTG H&CD (ICWC)TG diags (LIBS)TG Mat (W alloys)TG Transp

Emerging techno(Dust & T)

(Disrup.)


Highlights of 2008

Strong participation in PSI and IAEA 2008 > 20 oral papers (2 PSI review), > 100 publications

ITER fuel retention ITPA DivSOL • MIT meeting + IAEA + final report

Joint meeting (ITM / MHD / PWI) on disruptions

Preparation of WP2009 in new EFDA frame• Call for interest launched in Summer 08• Task agreements finalised early 09

Annual meeting Frascati Oct. 2008• reporting : WP2008 95% executed (5% delayed)


Definition of the Work Program for the next year(s)

Presentation of the n+1 annual WP to EFDA SC (main lines – ceiling) (Feb-March)

Call for Participation for n+1 WP (summer)

Answer to call (early Sept)Call assessment by PWI TF (end Sept)

Presentation to EFDA SC for approval (Oct)

Task agreements drafted for n+1 WP (Nov)Implemented by end of the year

SEWGs meetings

Annual PWI TF meeting, reporting on current WP

Timeline for the PWI TF

Next call : July 2009 for 2010


Work programme 2010-2011 :

major milestones


Main orientations for 2010-2011

• Strengthening of modelling for extrapolation to ITER and DEMO– Interpretative modelling for benchmarking tools used for ITER simulations

(SOLPS, ERO, DIVIMP …)– in close connection with ITM-TF (code development)

• 2 years WP : TA2010 and TA2011 will be very similar

• Integrated plasma operation : impact of impurity seeding– erosion, mixed material, fuel retention …

• Including recent ITER requests– disruptions/runaways– W R&D– divertor re-attachment heat loads– IC wall conditioning

• Bilateral collaborations :– mixed materials : PISCES (US) EFDA PWI TF

(EFDA call for long term visiting scientist, deadline August 15!)– material damage : plasma guns (RF) F4E, but modelling + dust = PWI TF


Materials

SEWG Material migration• Main wall erosion / redeposition• Impact of impurity seeding on erosion• Benchmark/development (gaps …) of local erosion/redep codes (ERO, …)

SEWG High Z• Impact of impurity seeding on W erosion• Control of W contamination : erosion (ELMs, ICRH) core W + interpretative modelling of W erosion and transport • Operation on damaged W PFCs + modelling of W damage & melt layer motion• Liquid metals

SEWG Material mixing• Binary systems : comparison lab vs tokamak mixed deposits• Impact of impurity seeding + thermal excursions (ELMs) on mixed material formation• Extension of transport codes to simulate material mixing at the walls • MD modelling of mixed material formation


Fuel retention / removal / dust

SEWG Fuel retention• Multi machine scaling of fuel retention benchmark for ITER prediction methodology• Post mortem : fuel location (gaps, bulk …) fuel removal

SEWG Fuel removal• Impact on dust production• IC wall conditionning• Removal in gaps

SEWG Dust• Dust conversion factor (gross erosion dust)• Metallic dust• Dust from maintenance, cleaning• Dust from transients (Bilateral collaboration with RF on plasma guns F4E)• Modelling of dust creation and transport

Coordination TG Diag / EFDA Emerging techno needed : indication of (+ F4E / ITER IO) other calls!



Disruptions• Particle and heat fluxes during disruptions (fast diags needed)

– Asymmetries (convective + radiative fluxes)– Runaways : modelling needed– Heat loads in mitigated disruptions (MGI)

• Optimisation of disruption mitigation (MGI), including runaways suppression– Modelling needed for MGI impact (penetration, radiation …)

Coordination MHD TG / ITM TF / F4E / ITER IO : joint meeting Feb 09

ELMs and inter ELMs heat loads• Heat fluxes for unmitigated vs mitigated ELMs • Main chamber : far SOL transport and fast particles• Heat loads during loss of detachment events

Material damage (Bilateral collaboration with RF on plasma guns F4E) • Modelling of material damage & melt layer motion benchmark vs plasma guns + tokamaks

SEWG Transients


0

1

2

3

4

5

6P

S (

pp

y)WP 2009TA 2009WP 2010

Total TA2009 : 22.6 ppy

(+ 4 ppy for new associations)

Total WP2010 : 23.75 ppy

EFDA emerging techno + F4E

High Z Disruptions

Resources for 2010 : priority support


• ITER : several top priority issues are PWI related (disruptions, ELMs, W R&D, diags for dust and T)

• EU PWI TF : reactive to ITER requests (ICWC, divertor reattachment)

Summary

• Coordination : European (other EFDA TF/TGs, F4E) and international (bilateral collaboration with US, ITPA)

• 2010-2011 work programme established : • Disruptions and high Z materials• Modelling for extrapolation to ITER and DEMO

• Next call : July 2009 (new tool: ECOM, deadline September 5)

• SEWG meetings : • fuel retention/removal/dust : June15-17, Cadarache• material migration / mixed materials : July 8-7, JET• transient heat loads / High Z : October 1-2, Ljubljana

• PWI TF meeting : November 4-7, Warsaw• PSI conference : abstracts due November 15

• Position for (young) scientist at PISCES under EFDA mobility !!! (deadline August 15)


Annex


ITPA : new organisation

ITPA (International Tokamak Physics Activity) has changedSummer 2008 : IEA (International Energy Association) legal framework of ITER

• Central coordinating committee : 3 representatives from each ITER partnerChair : R. Stambaugh (US), EU : J. Paméla, F. Romanelli, H. Zohm

• 7 ITPAs : Transport and confinement (S. Kaye, US)Energetic particles (S. Guenter, EU)Integrated operation scenario (S. Ide, JA)MHD stability (A. Sen, IN)Pedestal (H. Wilson, EU)Diagnostics (R. Boivin, US)Divertor and SOL (B. Lipschultz, US)

• New leadership for each group B. Lipschultz (chair), E. Tsitrone (co chair), R. Pitts (ITER co chair) selected

• Stronger connection to ITER organization : info + concerns both ways

• Coordinated experiments : DSOL (IEA on large tokamaks), international database







Fuel retention

Fuel retention Fuel Removal


ELMs and disruptions

Material erosion and transport in tokamaks

Material migration

Material migration

High-Z Materials

ITER-like Material Mix

Dust in fusion devices

Dust

Towards increased coordination …

F4E

F4E

EFDA Emerging Techno

Diag TG

MHD TG, ITM TF

H & CD TG

US : PISCES

US : PISCES

RF : plasma guns

RF : plasma guns


SEWG Proposed Task Agreements for 2010-2011

SEWG Fuel retention TA-1: Fuel retention analysis as a function of wall materials foreseen for ITER

SEWG Fuel removal TA-2 : Exploration of fuel removal methods compatible with retention in mixed materials and metals (Be)

SEWG Dust in Fusion Devices

TA-3: Dust generation and characterization in different devices

SEWG Material Migration TA-4: Erosion, transport and deposition of low-Z wall materials

SEWG High-Z Materials and Liquid metals

TA-5: Development of the PWI basis in support of integrated high-Z scenarios for ITER and Demonstration of liquid PFCs

SEWG ITER Material Mix TA-6: Determination of expected alloys and compounds and their influence on PWI processes

SEWG Transient Heat Loads

TA-7: Mitigation of disruptions and ELM and inter-ELM heat loads

WP2010: 7 Task Agreements proposed


Manpower BS (ppy)

Manpower PS (ppy)

Hardware PS (k€)

Mobility (k€)

TF CoordinationSEWG Coordination

11.75

TA-1: Fuel retention as a function of wall materials foreseen for ITER

7 3 50 50

TA-2: Fuel removal compatible with retention in different and mixed first wall materials

12 2 40 50


10 1.5 50 50

TA-4: Erosion, transport and deposition of first wall impurities

17 3 30 50

TA-5: Development of the PWI basis in support of integrated high-Z scenarios for ITER, Liquid plasma-facing components

22 4 80 50

TA-6: Expected alloys and compounds and their influence on PWI processes

9 2 30 50

TA-7: Mitigation of disruption loads for ITER,ELM and inter-ELM heat loads

14 5.5 120 50

Total 91 ppy 23.75 ppy 400 k€ 350 k€

Overview of resources requested for 2010

NB : resources requested for 2011 ~ same level


Overview of 2011 resources

Manpower BS (ppy)

Manpower PS (ppy)

Hardware PS (k€)

Mobility (k€)

TF CoordinationSEWG Coordination

11.75

TA-1: Fuel retention as a function of wall materials foreseen for ITER

7 3 50 50

TA-2: Fuel removal compatible with retention in different and mixed first wall materials

12 2 40 50


10 1.5 50 50

TA-4: Erosion, transport and deposition of first wall impurities

17 3 30 50

TA-5: Development of the PWI basis in support of integrated high-Z scenarios for ITERLiquid plasma-facing components

22 4 80 50

TA-6: Expected alloys and compounds and their influence on PWI processes

9 2 30 50

TA-7: Mitigation of disruption loads for ITERHeat load in ITER relevant ELM scenarios

14 6 120 50

Total 91 ppy 24.25 ppy 400 k€ 350 k€


Recent scientific achievements: Highlights of 2008


SEWG Material migrationMigration pattern refined, modelling

progressing• Erosion data in ITER relevant conditions (high particle flux / low energy) :

Pilot-PSI interpretation ongoing (geometry, surface temperature)

• Tracer experiments ongoing (13C) : AUG, Textor, TS

Tracer injection + post mortem + modelling

Main chamber inner divertor ok

Outer inner divertor ?

• N2 injection in lab experiments (PSI-2 …)

N2 scavenger effect confirmed. Tokamak ?[PSI08]

• Progress with the ERO code :

Gaps, effect of ELMs, higher CxDy

But : sticking probability, surface

roughness, redeposited layers re-

erosion

[FZJ]


SEWG High-Z MaterialsRadiation cooling with W walls, liquid limiters

Progress in W diagnostics : IR, spectroscopy

PWI basis for plasma operation with W walls (AUG) • Successful operation w/o boronisation confirmed• Boronisation radiation cooling essential reduced divertor heat loads

• Good performance in radiatively cooled plasmas (N2)

[PSI08, IAEA08]

1 µm

10 µm 1 mm

Irradiated W on W

Effect of neutron irradiation :

W specimen irradiated (0.25-0.75 dpa) Transient heat loads

Cracks but no melting. Microstructure ?[SCK-CEN, FZJ]

Liquid limiters :

Li in FTU, TJII : LLL (performance increased)

Ga in ISTOK [ENEA]

[PSI08]


• Scaling of fuel co-deposition with Be, C and W :

PISCES

Multi factor : Tsurf, impact energy, arrival flux ratio

revised modeling for T retention in ITER

reduction (x 0.5) of predicted inventory due to

temperature dependence

SEWG ITER Material Mix: Ternary systems explored, scaling for fuel codep ITER

Exploration of ternary systems : W-Be-C or Be-O-W

Lab experiments but also tokamaks (W-C in Textor)900 K

1120 K

1320 K

He+ ion fluence ~ 1–2×1026 m-2

Detailed study of PWI with W : PISCES

He & Be prevents blistering (300-700 K)

He driven growth of nanostructures (1070−1320 K)

suppressed with Be or C [PSI08]

[PISCES]


SEWG Fuel retention: Low fuel retention in full W AUG, gas balance vs post mortem

Low fuel retention in full W AUG

confirmed both from post mortem

and gas balance

C : codep in inner divertor

W : implantation in outer divertor 0.1

1

2002/2003 2004/2005 2005/2006 2007

Inner divertor Outer divertor Remote areas Total

D-I

nve

nto

ry in

300

0 s

[g]

Campaign

[IPP]

[PSI08]

Towards a reliable fuel retention assessment :

better consistency post mortem / gas balance

DITS project in Tore Supra

Significant contribution from gaps in erosion zone[PSI08, IAEA08]

Development of the LIBS technique (FZJ, CEA) : benchmarked against

post mortem on Textor tiles

Inner div

Outer div

Remote


SEWG Fuel removal ICWC optimization, first trial on gaps

Optimization of ICWC ongoing in Textor, Tore Supra, AUG

Homogeneity of ICWC plasma (B field)

Gas composition (He/D2)

[MedC]

[CEA]

Removal in gaps

thermo-oxydation (CIEMAT), ECR or GDC (IPP, FZJ),

laser (CEA), plasma torch (MedC)

[PSI08, IAEA08]

Dust production during cleaning processes :

laser cleaning (IPPLM, VR) : dust/flake production with significant fuel content


SEWG Dust Dust measurements during plasma, first dust injection experiments

Dust measurements during plasma operation :

CCD (TS, AUG), fast IR (AUG), electrostatic detector (TS),

Thomson scattering (FTU)

Dust collection ongoing : AUG, Textor, Tore Supra, FE200

Complex structure for C dust, spherical for W (droplets from transients ?)[PSI08]

[FZJ]

Preliminary dust injection

experiments in Textor

Driving force = j x B

Edge C increased, no effect in core


SEWG Transient heat loadsProgress in fast diagnostics, mitigation with MGI

Before (1.300 s), during (1.305 s) and after (1.310 s) the injection.

Unfiltered diodes [CRPP]

Transient heat loads : progress in fast diagnostics (IR, bolometry)

ELM filamentation, radiation during MGI

Hardware exchange foreseen (fast IR)

[PSI08, IAEA08]

Material damage : collab RF plasma guns (F4E) + Judith (repetitive ELMs)[PSI08]

Kinetic modelling of thermal loads

in gaps : peak heat flux 2-3 x larger than

tile surface (IPP.CR)

Mitigation of transients :

first experiments with RMPs on MAST dithering ELMs

MGI (TS, AUG, TCV …) : Radiation not axisymmetric. Runaways ?

Disruption avoidance with ECRH : ENEA, IPP[PSI08]

[IAEA08]

r. neu: sewg meeting, july 7-8, 2009 1 the eu plasma wall interaction task force : work programme...

Documents

sewg meeting

pwi tf slide

eu pwi tf

pwi tf end

iter context slide

annual meeting frascati

itpa cc meeting

disruptions material