Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 1

Contribution of Boron on the D retention in the AUG full-W wall regime

Max-Planck-Institut für Plasmaphysik

K. Sugiyama, M. Mayer, V. Rohde, K. Krieger, R. Neu

Max-Planck-Institut für Plasmaphysik, EURATOM Association

A. Hakola, S. Koivuranta, J. Likonen

VTT Technical Research Centre of Finland, Association EURATOM-Tekes

(WP10-PWI-01-01-02/IPP/BS)

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 2

Introduction

Internal view of AUG

Operation with full-W wall since 2007

• No boronization in 2007: extensive wall cleaning was done before the campaign to minimize the residual B in the vessel

• Regular boronization comes back since 2008: 5 boronizations in 2008 and 3 boronizations in 2009 campaign (~ 3.3 x 1023 B / boronization)

Clear reduction of C & O concentration in the plasma by boronizations

A. Kallenbach et al. Nucl. Fusion 49 (2009) 045007

Aim of this study

• Characterization of Boron deposition on the W surface

• Influence of Boron on the D inventory

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 3

Samples and analysis procedure

6A

6B

5

4

9A9B 9C

9D10

1

2

3A3B

Analyzed tiles from the divertor

Post mortem analysis

• Nuclear reaction analysis (NRA) using 2.5 MeV 3He+ for quantitative measurement of Boron, Carbon and Deuterium

• 2007: whole poloidal divertor set

• 2008: whole set without the roof baffle

Mostly PVD-W (3~5 m) coated tiles except for the outer target which was VPS-W

Total discharge time: 2620 s

• 2009: inner and outer target tiles

Analyzed tiles were exposed to 3 out of 5 boronizations

Total discharge time: 3410 s

Outer target (tile 1) was replaced by CMSII-W coated tile (~ 10 m).

Total discharge time: 5180 s

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 4

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

D

s-coordinate [m]

4.0

3.0

2.0

1.0

0

Are

al d

ensi

ty [1

018

cm-2

]

6A 6B 5 4 9A 9B 9C 9D 10 1 2 3A 3B

Poloidal distribution: 2007 campaign

Small amount of Boron deposition at inner private flux region

D retention more correlates with C deposition

NRA result from 2007 tiles: No boronization in 2007 campaign

6A

6B

5

4

9A9B 9C

9D10

1

2

3A3B6A

6B

5

4

9A9B 9C

9D10

1

2

3A3B

BDBD

0 0 . 2 0 . 4 0 . 6 0 . 8 1 1 . 2 1 . 4 1 . 6

DCBDCBDCB

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

D

s-coordinate [m]

4.0

3.0

2.0

1.0

0

Are

al d

ensi

ty [1

018

cm-2

]

BDC

BDC

0 0 . 2 0 . 4 0 . 6 0 . 8 1 1 . 2 1 . 4 1 . 6

DCBDCBDCB

0

100

200

300

400

500

Str

ike

poin

t [se

c]

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 5

Poloidal distribution: 2007 & 2008 campaigns

6B 5 4 9A 9B 9C 9D 10 1 2 3A 3B6A

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Are

al d

ensi

ty [1

018

B/c

m2 ]

s-coordinate [m]

2.0

1.5

1.0

0.5

0

0

100

200

300

400

500

600

700

Str

ike

poin

t [se

c]2007200820072008

B

B

B

B (W-stripe Left)

B (W-stripe Left)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

B

2008 tiles were exposed to 3 boronizations

Amount of Boron deposition clearly increased than 2007 by a factor of 3 - 5.

The thickest B deposition was found at private flux region

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 6

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6A

real

den

sity

[10

18 C

/cm

2 ]

4.0

3.0

2.0

1.0

0

5.0

6.0

Poloidal distribution: 2007 & 2008 campaigns

6B 5 4 9A 9B 9C 9D 10 1 2 3A 3B6A

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Are

al d

ensi

ty [1

018

B/c

m2 ]

s-coordinate [m]

2.0

1.5

1.0

0.5

0

2007200820072008

B

B

B

B (W-stripe Left)

B (W-stripe Left)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

B

C

2008 tiles were exposed to 3 boronizations

Amount of Boron deposition clearly increased than 2007 by a factor of 3 - 5.

The thickest B deposition was found at private flux region

B deposition pattern is similar to that of C

2007200820072008

B

B

B

B (W-stripe Left)

B (W-stripe Left)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 7

Are

al d

ensi

ty [1

018

D/c

m2 ] 4.0

3.0

2.0

1.0

0

Poloidal distribution: 2007 & 2008 campaigns

6B 5 4 9A 9B 9C 9D 10 1 2 3A 3B6A

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Are

al d

ensi

ty [1

018

B/c

m2 ]

s-coordinate [m]

2.0

1.5

1.0

0.5

0

B

D

2008 tiles were exposed to 3 boronizations

Amount of Boron deposition clearly increased than 2007 by a factor of 3 - 5.

The thickest B deposition was found at private flux region

B deposition pattern is similar to that of C

D retention on 2008 tiles did not change so much from 2007 tiles (influence of B is small..?)

20072008

20072008

B

B

B

B (W-stripe Left)

B (W-stripe Left)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

20072008

20072008

B

B

B

B (W-stripe Left)

B (W-stripe Left)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

20072008

20072008

D

D

D

D (W-stripe Left)

D (W-stripe Left)

20072008

20072008

D

D

D

D (W-stripe Left)

D (W-stripe Left)

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 8

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Are

al d

ensi

ty [1

018

B/c

m2 ]

4.0

2.0

0

8.0

6.0

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6A

real

den

sity

[10

18 D

/cm

2 ]

4.0

2.0

0

8.0

6.0

Poloidal distribution: 2007 to 2009 campaigns

6B 5 4 9A 9B 9C 9D 10 1 2 3A 3B6A

B

D

2009 tiles were exposed to 3 boronizations

Further increase of B deposition at the private flux region (note that 2009 tiles were employed longer time (5180 s) than usual (~ 3000 s)

D retention at the private flux region shows also increase (because of the codeposition with B?).

2007 20082009

2007 20082009

D

D

D

D (W-stripe Left)

D (W-stripe Left)

DDDD (W-stripe Left)D (W-stripe Left)DD

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

2007 20082009

2007 20082009

D

D

D

D (W-stripe Left)

D (W-stripe Left)

DDDD (W-stripe Left)D (W-stripe Left)DD

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

200720082009

200720082009

B

B

B

B (W-stripe Left)

B (W-stripe Left)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

BBBB (W-stripe Left)B (W-stripe Left)BB

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

200720082009

200720082009

B

B

B

B (W-stripe Left)

B (W-stripe Left)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

BBBB (W-stripe Left)B (W-stripe Left)BB

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 9

10

100

1000

10000

100000

0 1000 2000 3000 4000

Time [s]

SIM

S in

tens

ity [

arb.

uni

t]

Depth profiles of B and D

SIMS profiles of D and B on 2009 tiles measured at VTT

Depth profiles of B and D show sometimes nice correlation, but sometimes not...

10

100

1000

10000

100000

0 1000 2000 3000 4000 5000

Time [s]

SIM

S in

tens

ity [

arb.

uni

t]

B

D

12CW

BD

12CW

s = 0.44 m s = 0.49 m

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 10

1.00E+21

1.00E+22

1.00E+23

2006 2007 2008 2009 2010

Campaign

Am

ount

in 3

000

s [a

tom

s]

D

C

B

Evolution of B deposition and D inventory

1.00E+21

1.00E+22

1.00E+23

2006 2007 2008 2009 2010

CampaignA

mou

nt in

300

0 s

[ato

ms]

D

C

B

Inner Divertor target: tile 4 Outer Divertor target: tile 1

Increase of D retention in the boronization phase was not as much as the increase of B deposition.

At the moment, contribution of B to D retention seems to be limited.

VPS-W CMSII-W

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 11

0.00E+00

1.00E+18

2.00E+18

3.00E+18

4.00E+18

5.00E+18

6.00E+18

7.00E+18

8.00E+18

9.00E+18

0.360 0.410 0.460 0.510

s-coordinate [m]

Am

ount

of

B s

epos

ition

[B

/cm

2]

B deposition on 2009 marker stripes

• Deposition efficiency depends on the substrate material: the efficiency is less on the W compared to C surface.

• D retention shows also substrate dependence (by A. Hakola)

Influence of substrate material

B on C stripe

B on W stripe

Inner Divertor target: tile 4

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 12

Summary

Boron deposition on the full-W divertor

Amount of B deposition on the W divertor during the regular boronization phase increased compared to the no-boronization phase by a factor of 3 - 5.

B deposition distribution is similar to C deposition distribution: major deposition is found in the private flux region.

Deposition efficiency has the substrate dependence: Lower deposition efficiency on the W surface than C surface.

Contribution to the D inventory in AUG

Contribution is limited at the moment:

- increase of D retention in the boronization phase was not as much as the increase of B deposition.

Codeposition of B and D can enhance D retention (some of SIMS data showed nice correlation of B and D), nevertheless, C seems to play important role for D trapping.

Influence of B (on the W surface) on the D accumulation in the W bulk is not clear because AUG has only W-coatings (Do we need lab. experiment?).

Kazuyoshi Sugiyama, SEWG meeting on Fuel retention, Garching, July 20 2010 14

AUG divertor: Evolution of D inventory

All-W machine

• Decrease of total D-inventory by factor 5 ~ 10

from C-dominated to all-W (by the decrease of C and B)

• D-inventory in outer target tile is dominated by trapping in VPS-layers.

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

M. Mayer et al. PSI 2008