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PWI - related work at VR

Marek Rubel (VR)Projects within ILW : • Beryllium coatings for inner wall cladding (with MEC, UKAEA, FZJ, UCSD, TEKES)

• Development of Beryllium marker tiles (with MEC, UKAEA, UCSD, FZJ )

• Erosion – Deposition diagnostics (with UKAEA, FZJ, IPP, CRPP)

First Mirror Test in EP-1 and EP-2 (with CRPP)

Fuel Inventory, Material Migration and Material Mixing:• Studies of inventory in PFC from JET and TEXTOR (with UKAEA, TEKES, FZJ)

• Tracer Techniques (13C) in material migration studies (with group of Associations)

• In-depth migration of fuel in carbon-based materials (with FZJ, SFA)

• Microanalysis of fuel distribution on PFC (with FZJ, SFA)

• New phase formation on tungsten PFC (with IPPLM, FZJ)

• Deposition and fuel inventory in castellated Be and W tiles (with UKAEA, FZJ)

• Surface state of PFC and dust formation related to fuel removal by oxidation,

annealing and photonic cleaning - laser, flash-light (with FZJ, UKAEA, IPPLM)

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Be toroidal belt limiter

• Operation: 1989 – 1992

• 56 000 s of plasma

• 2000 castellated blocks.

Studies performed on two tiles:

Castellated grooves: both sides of 6 grooves;

Side surface between the tiles;

Top surfaces of tiles.

Deposition and Fuel Inventory in Castellated Beryllium Limiters from JET

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Top and Side Surfaces of CleavedBeryllium Limiter Tiles

Cleaved limiter blocks mounted in the chamber for Ion Beam Analysis

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Deposition in the Castellated Grooves of the Beryllim Limiter Tiles

Side A Side B

Surfaces in thecastellated groove

Freshly cleavedsurface

Freshly cleavedsurface

0

3

6

9

12

15

18

0 3 6 9 12 15

Distance from Plasma [mm]

D a

nd

C [

e17/

cm2]

]

D, Side A

D, Side B

C, Side A

C, Side B

Messages:• Deuterium deposition in the castellation always associated with Carbon

• Short decay lenght of deposition in the castellation: = 1.5 mm.

• D content in the castellated groove does not exceed 7 x 1017 cm-2.

• No deuterium detected in bulk beryllium.

Modelling of transport into castellation is ongoing: CEA, CRPP, FZJ, IPP.CR

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VERY TENTATIVE scaling to tritium inventory in ITER

Assumptions:

Only 50 % of deuterium remained after 14 years of tile storage(based on studies of carbon PFC after long-term storage in air, M. Rubel)

Deuterium : Tritium retention: 1:1

Area of castellated beryllium tiles: 700 m2

1 ITER shot: 0.5 - 1 year (energy input) or 4 years (fluxes) of JET operation(based on calculations by V. Philipps)

• 0.4 g T / ITER shot (based on energy input)

• 2.3 g T / ITER shot (based on fluxes)

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Tungsten – Oxygen in castellation of W brush limiter

exposed in TEXTOR

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Castellated limiter exposed at TEXTOR

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Castellated limiter exposed at TEXTOR

WWWW WWO WW

W

W

1 2 3 4 5 6 7 8 9 10 11 12

keVFull Scale 292 c ts Cursor: 0.297 (1 cts )

1

WW WW WWW W

W

W

1 2 3 4 5 6 7 8 9 10 11 12

keVFull Scale 226 c ts Cursor: 0.315 (0 cts )

2

Messages:

„Nice design” on the limiter contains W and O.

Very recent result of XRD analysis: WO2. (IPPLM, M. Psoda)

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Castellated limiter exposed at TEXTOR

WO2 leaves

Questions: Is it a condensed volatile stoichiometric tungsten oxide?If YES, how and why was it formed?What was the source of oxygen? Non-oxygen free Cu?