PIIM laboratory Aix-Marseille Université - CNRS Marseille ...Ogorodnikova . et al. J. Nucl. Mater....

Bridging model and real systems with laboratory experiments: dynamic retention of deuterium in tungsten

Régis Bisson

PIIM laboratory Aix-Marseille Université - CNRS

Marseille, France

Trieste ICTP-IAEA, November 2014

Bridging model and real systems with laboratory experiments: summary of common laboratory experiments

Trieste ICTP-IAEA, November 2014 1

• same parameters, similar retention but different TPD profile: sample preparation?

Ogorodnikova et al. J. Nucl. Mater. 313-316, 469 (2003)

Tian et al., J. Nucl. Mater. 399, 101 (2010)

200 eV/D F=3.1024 D/m2

Ogorodnikova et al., Phys. Scr. T138, 014053 (2009)

Ogorodnikova et al. J. Nucl. Mater. 313-316, 469 (2003)

Bridging model and real systems with laboratory experiments: summary of common laboratory experiments

• same parameters, similar retention but different TPD profile: sample preparation?

• different apparatuses used for D implantation and TPD retention measurement

air exposure generates many deuterated products than cannot all be recorded

underestimation of retention [Wang et al. Nucl. Instr. Meth. Phys. Res. B 300, 54 (2013)]

Tian et al., J. Nucl. Mater. 399, 101 (2010)

200 eV/D F=3.1024 D/m2

Ogorodnikova et al., Phys. Scr. T138, 014053 (2009)

Trieste ICTP-IAEA, November 2014 2

3

• Retention measurement best approach: all-in-situ apparatus (no air exposure)

• a rare example in the literature: Ogorodnikova et al. J. Nucl. Mater. 313-316, 469 (2003)

Flux: 1019 D.m-2.s-1

Fluence: 1021-1024 D.m-2 Ts: 300 K Ek: 200 eV/D

Ogorodnikova et al.


Bridging model and real systems with laboratory experiments: selecting “ideal” conditions

4

• Retention measurement best approach: all-in-situ apparatus (no air exposure)

• a rare example in the literature: Ogorodnikova et al. J. Nucl. Mater. 313-316, 469 (2003)

Flux: 1019 D.m-2.s-1

Fluence: 1021-1024 D.m-2 Ts: 300 K Ek: 200 eV/D

Ogorodnikova et al. this work

1016 D.m-2.s-1

1017-1021 D.m-2 300 K 250 eV/D

• in Aix-Marseille University (AMU): our W samples present a single low temperature

desorption peak (low defect density)



5

Polycrystalline sample with low defect concentration - Annealed at (1573 K ; 1h) in vacuum by A.L.M.T. (Japan) - Electro-polished in-house for mirror finish - Annealing at 1300 K in ultra-high vacuum



this work

1016 D.m-2.s-1

1017-1021 D.m-2 300 K 250 eV/D

6

Polycrystalline sample with low defect concentration - Annealed at (1573 K ; 1h) in vacuum by A.L.M.T. (Japan) - Electro-polished in-house for mirror finish - Annealing at 1300 K in ultra-high vacuum

differentially pumped

QMS chamber


Bridging model and real systems with laboratory experiments: the AMU apparatus

7


QMS chamber

D2+



8


QMS chamber

D2



9

• Absolute calibration of the TPD in desorption rate (D2/s) and retention (D/m2) checked with NRA measurements (JSI, Slovenia)

•Absolute retention sensitivity down to 1017 D.m-2


QMS chamber

D2



10

[1] Ogorodnikova et al., J. Nucl.Mater. 313-316, 469 (2003)

• retention orders of magnitude smaller than implantation probability from SRIM model

• non-linear dependence of Retention α Fluence0.50-0.66

Bridging model and real systems with laboratory experiments: retention measurements: extending to low fluences



Bisson et al., in preparation 11

• retention orders of magnitude smaller than implantation probability from SRIM model


Retention α Fluence0.40-0.60



12 Bisson et al., in preparation

• retention similar to SRIM implantation probability when reaching low fluences






• discrepancy in the 1021 D/m2 range where different fluxes were used

Bridging model and real systems with laboratory experiments: retention measurements: explaining discrepancies







• discrepancy in the 1021 D/m2 range where different fluxes were used … i.e. different implantation duration

• could it be that release (desorption) of deuterium occurs during implantation ?!

2 min

24 hour








• could it be that release (desorption) of deuterium occurs during implantation ?!


repeated this implantation many times with different storage time

between the end of implantation and

the TPD measurement




Deuterium release on the time scale of hours and days

Release of deuterium during long implantation (explains the discrepancy in the 1021 D/m2 range between our data and

Ogorodnikova et al. data)

16 Bisson et al., in preparation Trieste ICTP-IAEA, November 2014




Best fit obtained with a double exponential decay (with a constant): at least 3 populations of traps… but a single desorption peak !




Best fit obtained with a double exponential decay (with a constant): at least 3 populations of traps… but a single desorption peak !

18 Bisson et al., in preparation Trieste ICTP-IAEA, November 2014




The single desorption peak has a structure “evolving” with storage time: it is composed of several sub-peaks

Several trapping energies are related to the low desorption temperature peak (at least 3 trapping energies from previous retention decay analysis)



Bridging model and real systems with laboratory experiments: origin of the dynamic retention of deuterium

a single TPD peak =

at least 3 trapping energies

Bisson et al., in preparation Fernandez, Kato, Ferro, in preparation

“a single trap: the W vacancy” =

at least 4 groups of trapping energies for 300 K implantation

DFT calculations + statistical model PIIM lab + NIFS (D. Kato) 20 Trieste ICTP-IAEA,

November 2014

Bridging model and real systems with laboratory experiments: double checking the origin of the dynamic retention of deuterium

21 Trieste ICTP-IAEA, November 2014 Bisson et al., in preparation

At low fluences: retention = SRIM implantation probability:

dynamic retention is non operative

Why? deuterium density is low (10-5 at. density)

mostly 1H or 2H-vacancy complexes (VH1-2)

Fernandez, Kato, Ferro, in preparation

22

VH1-2 complexes: binding energy is high desorption temperature should be higher for low fluences…



Bisson et al., in preparation





Fernandez, Kato, Ferro, in preparation

23

VH1-2 complexes: binding energy is high desorption temperature should be higher for low fluences… this is verified







Bisson et al., in preparation


Bridging model and real systems with laboratory experiments: summary

• all-in-situ apparatus • implantation at 300 K ; TPD up to 1300 K • retention measured down to 1017 D/m2

• observation of D release at 300 K • on at least 3 time scales • with an evolution of the TPD peak • consistent with W vacancy trap filling

R. Bisson, C. Grisolia (CEA), T. Angot Researchers O. Saïdi, F. Ghiorghiu PhD students S. Markelj (JSI, Slovenia) visiting scientist (Euratom) O. Mourey Master student J.-B. Faure Mechanical engineer

€ from ANR, CNRS, AMU, EFDA/EUROfusion


• all-in-situ apparatus • implantation at 300 K ; TPD up to 1300 K • retention measured down to 1017 D/m2

Bridging model and real systems with laboratory experiments: summary

• observation of D release at 300 K • on at least 3 time scales • with an evolution of the TPD peak • consistent with W vacancy trap filling

Starting 2015 an extensive “model experiment – theory” collaboration on D retention in tungsten through a project supported by the A*MIDEX foundation (Aix-Marseille Université)

a large set of samples (single and poly-crystals)

surface and bulk preparation techniques (e-/p+/Wn+ accelerators, surface science) complete set of analysis tools (TPD, XPS, SEM, TEM, NRA, SIMS, PAS…)

multi-scale modeling approach (DFT, OKMC, MRE)


Bridging model and real systems with laboratory experiments: perspectives

Y. Ferro, C. Becquart, C. Grisolia, B. Rousseau, R. Bisson, T. Angot, G. Cartry, C. Pardanaud, C. Martin, P. Roubin, M.-F. Barthe, L. Gallais… PIIM, Fresnel, CEA, CEMHTI, UMET, LSPM…

Thank you for your attention

PIIM laboratory Aix-Marseille Université - CNRS Marseille ...Ogorodnikova . et al. J. Nucl. Mater....

Documents

Transcript of PIIM laboratory Aix-Marseille Université - CNRS Marseille ...Ogorodnikova . et al. J. Nucl. Mater....