in-vessel dust&tritium management* 1 *based on the report of a european group of experts on...

In-Vessel Dust&Tritium In-Vessel Dust&Tritium Management*Management*

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*Based on the report of a European Group of Experts on In-Vessel Dust & Tritium ManagementP. Coad, G. Counsell, J. Furlan, C. Grisolia, F. Le Guern, D. Maisonnier, A. Murari, V. Philipps, S. Rosanvallon, J. Roth, E. Tsitrone

A. Malaquias and the Collaborators in the Associations

WP09-DTM-TritI-RWP09-DTM-DustI-R

INTRODUCTION INTRODUCTION

ON GOING R&D PROGRAMME ON GOING R&D PROGRAMME

DUST AND TRITIUM MANAGEMENTDUST AND TRITIUM MANAGEMENT

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Combined request from F4E&EFDA Combined request from F4E&EFDA managements:managements:

Establish the status of the R&D on:Establish the status of the R&D on:• In-vessel dust and tritium inventory In-vessel dust and tritium inventory

measurement techniquesmeasurement techniques• In-vessel detritiation and dust removal In-vessel detritiation and dust removal

techniques techniques

Propose objectives for an R&D programmePropose objectives for an R&D programme

Introduction (1/2)

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Decision to gather European experts including PWI TFLs, Decision to gather European experts including PWI TFLs, JET TF_FT and JET TF_D TFLsJET TF_FT and JET TF_D TFLs

Members P. CoadG. CounsellJ. FurlanC. Grisolia F. Le GuernD. MaisonnierA. MurariV. PhilippsS. RosanvallonJ. RothE. Tsitrone

UKAEA-Deputy Task Force Leader Fusion Technology-JETF4EF4ECEA-Task Force Leader Fusion Technology-JET EFDA European CommissionENEA-Task Force Leader Diagnostics-JETFZJ-JET ILW Project ScientistCEA-Project Leader on DustIPP- Task Force Leader Plasma Wall InteractionCEA-Deputy Task Force Leader Plasma Wall Interaction

Introduction (2/2)

WP09-DTM-DUSTI-R and WP09-DTM-TRITI-R

aimed at identify and develop diagnostic and removing systems for D&T for ITER

Demonstrate a clear need for the system (i.e. what ‘gap’ does it address)Conduct proof-of-principle studies to show feasibility

In case of positive outcome (installation on ITER being feasible), a programme for assessment of the techniques in view of its installation on ITER, will be defined.

• Divertor erosion monitor– technology to be defined (Dualλ speckle or LIDAR are candidates)– currently allocated lower (divertor) port #14– intended to measure erosion and deposition

• Local dust measurement system– technology to be defined (capacitance microbalance a candidate)– currently allocated lower (divertor) port #04– 8 locations distributed under 2 divertor casettes

• Removable samples– mounted in well-shadowed regions, removable independent of cassette by in-vessel manipulator during shutdowns– collect dust and deposits (tritiated)

• Local surface tritium analyser– LIBS technology– deployed by in-vessel manipulator during shutdowns

• In addition, development of In Vessel Viewing System (IVVS)

D&T Diagnostics in ITER baseline

In baseline -

• Vacuum cleaning RH tool

– for use during divertor cassette replacement

• Qualification of divertor bake-out system for 350oC

Under consideration –

• Liquid flushing of vacuum vessel

• Vacuum cleaning tools for in-vessel manipulator

Removable D&T ITER systems

Measurement requirements in ITER

Parameter Range or Coverage

ResolutionAccuracy

Frequency Spatial

Divertor erosion Erosion rate 1 – 10 x 10-6

m/s 2 s 10 mm 30%

Net erosion 0 – 3 mm Per pulse 10 mm 12 x 10-6 mDust monitoring

Dust accumulation rate

10-4 - 10 2‑

kg/m2/pulse Per pulse Several positions

50% abs20% repr

Dust concentration

10-2 – 10kg/m2 Daily Several

positions50% abs20% repr

Tritiummonitoring

H, D, Taccumulation rate

2x1019 - 2x102

1

at./m2/pulsePer pulse Several

positions50% abs20% repr

H, D, T concentration

1020 – 2x1024

at./m2 Daily Several positions

50% abs20% repr

Most reports received

J. Wolowski, M. Kubkowska, M. Rosinski, P. Gasior

IPPLM Warsaw, Poland

MAIN GOAL:

DEM system: to perform a review of possible laser-based techniques which could be employed together with a detailed feasibility study for the possible integration on ITER

WP1.1 Divertor Erosion Monitor – study on application of laser-based techniques for real-time diagnostics of ITER divertor erosion

Status at KoM

WHAT SHOULD BE FOUND?

time resolution (integrated)

Spatial resolution

What area we will be able to cover and will it be enough?

What sensitivities will we be able to obtain for parameters

and how will it correspond to the sensitivity on amounts of the eroded material

How other variables as temperature, vibration, radiation will influence our

measurements and what countermeasures can we introduce to reduce their

Interference?

WHICH PORTS CAN WE USE?

WHAT ARE THE DISTANCES AND ANGLES?

WHAT IN FACT CAN WE PUT INTO A PORT?


existing systems

Nd:YAG laser system, up to 0.6 J, 3 ns pulses at 1064 nm, repetition rate from single shots to 10 Hz, up to 6 W of average power


Yb:fiber laser system, with ~100 ns pulses of 1 mJ, up to 100 kHz repetition rate, up to 100 W of average power


Spectrograph Mechelle5000ICCD camera

(intensified CCD)


Status at intermediate report D1

laser techniques useful for DEM• spectroscopy • speckle interferometry

system to provide the laser beam into the divertor (probably needs adaptative optics)• rotating mirror • rotating head of a fiber laser

Time resolutions of 2-10 kHz (integrated) may be achieavable with fiber laser

The laser head drawings suggest that not the whole area of the divertor can be seen; available actuators and motors can provide rotating capability to the head to reach otherwise unavailable regions.

The work for the next few months will include:detailed investigations of the spatial coverage of the laser beam,study and development of the light collecting system both for interferometry and spectroscopy


ITER BaseLine: currently allocated lower (divertor) port #14

Technology to be defined (Dualλ speckle or LIDAR are candidates)

F4E – will place Grants for advancing the Divertor erosion monitor conceptual

designs. Call for Proposals in Q3 2009. DEM aspects needs close collaboration

with WP09-DTM-DUSTI-R

IVVS for DEM - Target metrology of <0.5mm over 70% of first wall seems

possible.

Design team has achieved 0.15mm (e.q. 200Kg Be FW) in lab and R&D

continues


Other works on-going

WP1.2 - To perform a feasibility study in order to check a potential port-plug application of the Speckle interferometry on ITER

• E. Gauthier

• Association Euratom - CEA Cadarache, IRFM

• H. Van der Meiden

• Association Euratom - FOM, NL

Status at KoM

Accessibility in ITER divertor:- Optical design- ITER environment constraints

Proposal: Speckle Diagnostic on Magnum PSIInterfaces requirements (models, volumes, port, vibrations def)


2

Phase images at 2 different wavelength Phase images at 2 different wavelength 11 and and 22 1

unwrapped Phase

Phase modulo 2 π

Pixels

Phase

4 π

2 π

1) Spatial phase unwrapping 2) PHASE conversion IMAGE 3D

Transformation for shape measurementTransformation for shape measurement

),(2

),( yxi

yxz

Height [µm]

Y [

pix

els

]

X [pixels]

i

Substraction

21

21

22

i

Phase image at synthétique wavelength Phase image at synthétique wavelength

),(2

),( yxzi

yx withwith

0

2


Status at KoM

Erosion measurement on CFC

• Good agreement between microscopy and Speckle interferometry

Ablation A Ablation B Ablation C

Depth (µm)

Speckle Interferometry 192 ± 12 260 ± 20 490 ± 25

Confocal microscopy 200 ± 10 270 ± 10 480 ± 10

Ablation A

Vertical profile

195 10 µm

Horizontal profile

192 12 µmX=4120 µm

Y=1890 µm

Spatial distribution

Status at KoM


Speckle interferometry system on ITER– LASER based depth probing techniques (Speckle interferometry at

2-wavelength).

– Measure both erosion and deposition

– Lasers located at ~40 m

– Optical design very complex

Status at KoM


Proposal for a real time erosion diagnostic on Magnum PSI

Status at KoM


WP1.3 - To review the spectroscopy diagnostics foreseen on ITER to check their adequacy for erosion measurements

J. Wolowski, M. Kubkowska, M. Rosinski, P. Gasior

IPPLM Warsaw, Poland

Status at KoM

Succesful monitoring of the process of thick co-deposite removal from TEXTOR samples

Swan system – C2(d3Πg-a3Πu) – may be used to estimate temperature

Spectrum taken for a cleaned surface (after 40 shots) – no evidence of deuterium

Conclusion:

-Fuel species are present in relatively thick co-deposit layer, which is removed after 30-40 laser pulses.

- The spectrum consists of carbon lines and Swan bands which can give information on plasma parameters during the process of removal

Spectrum taken for a codeposited surface (first series of 5 shots) – deuterium line can be clearly seen


Status at intermediate report

The work for the next few months will include:study of the systems forseen for ITER and adaptation of their parameters to obtain as much diagnostic information as possible.

material mix focus on some specific areas in which lines of Deuterium, Carbon and Tungsten may be observed with a good signal to noise ratio and good repeatability. The research conducted at IPPLM suggested that such areas for deuterium and carbon comparison lies in the range of 650-660 nm and for carbon and tungsten ~420-430 nm.

Use of two main approaches for spectroscopic measurements:• Plasma as a source for excitation of PFM• Laser for generating the plasma on the solid surface

No concrete studies for ITER yet


WP2.1 - To assess the possibility (including integration issues) of using a photo-cleaning method for removing the dusts deposited on the divertor surfaces

(Lasers, Plasmas and Photonic Processes Laboratory (LP3)

and CEA Cadarache)P. DELAPORTE (LP3) & C. HERNANDEZ (CEA)

Status at KoM

Laser removal of ITER – like particles is studied since 2 years at LP3 laboratory in close collaboration with CEA Cadarache.

Some experiments are still needed to complete the study, but most of the processes, andirradiation conditions, have been determined.

(F4E - Under consideration – Liquid flushing of vacuum vessel - Vacuum cleaning tools for in-vessel manipulator)

1. Theoretical modeling of the laser heating of the ITER- like “etalons”.

The activities necessary to perform this task are divided in 3 sub-tasks :

2. Experimental studies on surface cleaning by laser heating.

3. Integration on a Remote Handling system


Status : 3D modelling was realised and compared with 1D modelling

Status at intermedium report

1. Theoretical modeling of the laser heating of the ITER- like “etalons”.


Status in common with Tasks WP3.2, WP4.4 & WP4.5:

Pre-Design of two Remote handling systems to perform :

- LIBS analysis for Tritium inventory

- Heating for Tritium removal

- Laser ablation and waste collection

The first system will be able to be used without pressure break (between two plasma sessions) and the other one during maintenance phases.

2. Experimental studies on surface cleaning by laser heating

3. Integration on a Remote Handling system



Experimental scheme is under modification for studies on surface cleaning by laser heating.

Remote Handling system development

- Design continuation

- Constraints linked to the two designs (for the process, for the carrier)

- Benefits / limitations for the two designs.

High repetition rate laser system for surface heating or ablation



WP3.1 - To perform a feasibility study on non-invasive methods: Port-plug based scanning laser system, preferably with parallel light collection optics (LIDS, LIAS, LIBS)

V. Philipps, for the FZJ Laser diagnostic team( A. Huber, B. Schweer, J. Coenen , H.G.Esser, M. Zlobinski,

N. Gierse, G.Beyene)…H.J. van der Meiden FOM

A. Semerok CEA….

(Laser induced desorption spectroscopy (LIDS), Laser induced ablation spectroscopy (LIAS), Laser induced breakdown spectroscopy (LIBS))

Status at KoM

Laser induced desorption spectroscopy (LIDS) LIDS has been tested and demonstrated in R&D on TEXTORH inventory in TEXTOR C- deposits measured in situ Lower detection limit under TEXTOR conditions: 3-10 x1016 D/cm2 (depending on geometry and plasma conditions)

Laser induced ablation spectroscopy (LIAS)Systematic studies of laser ablation of bulk C, W and C deposits on C and W in lab experiments (ongoing)

Laser induced breakdown spectroscopy (LIBS) No LIBS experiments/experience at that timePlan: LIBS induced light to be detected in lab device and in TEXTOR (end 2009 / beginning 2010)



• LIDS has been further qualified for fuel retention measurements on different CFC materials, including the previous and new ITER CFC material (NB31, NB41). • LIDS on W materials exposed to TEXTOR plasmas and laboratory plasma experiments has been started• In TEXTOR, work on coaxial LIDS light detection has been started


LIAS: Extensive basic R&D has been done on laser ablation (10ns Ruby laser) of bulk graphite at various energy densities. Experiments on ablation of carbon layers (a-C:H on C and W) have been started.

LIBS: A wide range (350 nm -720nm) , high resolution (λ/∆ λ = 20000) Echelle spectrometer has been procured and taken into operation. First LIBS measurements in the laboratory on bulk graphite have been performed showing appearance of CI-CIV carbon ions.

Modelling - For application of LIDS and LIAS in ITER, extensive B2-Eirene modelling has been started.

-Assessment of ITER ports for application of laser based diagnostics has been started. First analysis favours the port plug in the equatorial plane and at the dome.

-A principle set-up for a coaxial beam injection and observation system has been developed.

-The laser beam properties for LIDS and LIAS (LIBS) for application at ITER are determined: First parameter for the necessary laser beam expander and diameter of the focussing mirror are developed.

- B2-EIRENE calculation on H - light distribution the parameters for a coaxial observation system, located at the midplane port, have been evaluated.



3. Technical implementation of LIDS, LIAS and LIBS in ITER

WP4.4 - To perform a feasibility study envisaging a possible implementation of a photonic heating technique on the IVVS carrier or a robotic arm system

A.Semerok, D. Farcage, A. Leontyev, P.-Y. ThroCEA Saclay, FranceC.

HernandezCEA Cadarache, France

Status at KoM

The developed compact system (called LASK) is a Remote Handled system. It can be plug on a robotic arm system or a multipurposedeployer (MPD) to be used at a pressure range from atmospheric to10-6Pa and a Temperature up to 200°C.


Status in common with Tasks WP3.2, WP4.4 & WP4.5:

Pre-Design of two Remote handling systems to perform :

- LIBS analysis for Tritium inventory

- Heating for Tritium removal

- Laser ablation and waste collection

The first system will be able to be used without pressure break (between two plasma sessions) and the other one during maintenance phases.



WP4.5 - To proceed with a feasibility study on a potential remote handled application of a photonic ablation technique on ITER, emphasising the need to guarantee an efficient collection of the wastes

(CEA Cadarache and CEA Saclay)C. HERNANDEZ & A. SEMEROK

1. Dust characterization after laser treatment

2. Evaluation of efficiency and limitations of two wastes

collection systems by respect to ITER and carrier

constraints

3. Development of a Remote Handling system usable on a

dedicated carrier to perform tritium removal (with a

photonic ablation technique) and an efficient collection of

the wastes

4. Impact of ITER conditions on a Remote Handling system

able to perform laser ablation and wastes collection

Status at KoM


Sub-tasks:

Status at KoM


Status at KoM

Vacuum vessel for dust collection validation under different environment conditions and embedded LIBS system validation



Microparticles size dispersion measurements (in the range 10nm -10µm) will be performed with the ablated matter collected in the sealed cell. The ablation will be performed with an high repetition rate Yb-fiber laser (20kHz, 1 mJ/puls, 1,06 µm wavelength) in the cleaning and detritiation regimes.

Sealed cell for ablated matter collection

Yb-fiber laser inside protecting box


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• commentscomments

5 working packages left from 2009 will make part of a new Work 5 working packages left from 2009 will make part of a new Work Programme in 2010Programme in 2010

In some of the on-going tasks Potential techniques have been reviewed In some of the on-going tasks Potential techniques have been reviewed and the most relevant selectedand the most relevant selected

Some activities are not yet start or achieved a reasonable development Some activities are not yet start or achieved a reasonable development state – it will be closed followstate – it will be closed follow

Feasibility studies must be completed in order to support a decision on Feasibility studies must be completed in order to support a decision on further project proposals for 2010 and beyondfurther project proposals for 2010 and beyond

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