materials development for ife systems documents/ife/20… · second research coordination meeting...

Materials development for IFE systems

Dr. Raquel González Arrabal

[email protected]

Instituto de fusión nuclear

mailto:[email protected]

Raquel González Arrabal Second Research Coordination Meeting of the Coordinated Research Project on Pathways to Energy from Inertial Fusion: Materials beyond

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Outlook

• Motivation

• Final optics

– Development of engineering solutions for proper

performance of the final lenses

• Plasma Facing Materials.

– Thermomechanical effects

– Role of grain boundaries on:

• Radiation induced-damage

• Light species behaviour

• Conclusions


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Motivation

One of the main bottle neck for fusion to become a reality

is the lack of materials able to withstand the harsh

radiation environment:

•Atomistic damage

•Thermal loads

•Materials qualifications in existing facilities


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Motivation

Development of radiation-resistant materials


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ICF plant – Direct drive

• The problem:

• Considering only neutron

irradiation a non-uniform

temperature profile is

rapidly reached

A. R. Paramo et al. Nucl. Fusion 54 (2014) 123019 (11pp)


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Temperature requirements

• Temperature below the service limit (<1223 K)

At least partial

ion mitigation

is needed



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Ion Mitigation

A. R. Paramo PhD thesis


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Formation of ColourCentres

Latkowski et al, Fusion Sci. Technol 43 (2003) 540-58

Marshall et al, J. Non-Crsyst. Solids 212 (1997) 59-73

Neutrons cannot

be mitigated


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Temperature requirements

• Temperature below the service limit (<1223 K).

• High temperature to minimize the formation of color centers (> 800 K).

• Constant temperature during the operation of the plant (σrms < 1%).

A. R. Paramo PhD thesis


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Temperature control

• Counter flow configuration

• Transparent to the HiPER

laser wavelength (350 nm)

• Windows 15 mm (>800K)

• Fluid Temp ~950K

• Pressure 100 kPa /

Pressure drop 1 kPa

• Minimize channel width to

minimize flow

• Four fluids studied (He,

CO2, Ar, Xe)



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Conclusions: final optics

•We have proposed an ion mitigation

system.

•We have developed an engineering

system which, allows keeping the

lens temperature constant during

start up and operation.


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PFM

Nowadays, W has been proposed to be one of the best candidates forPFM.

But….

– Fragility (T≤400ºC) limits its operation temperature (DBTT

<T<~1300ºC)

– Atomistic effects: cracking and exfoliation

Development of new materials

Exfoliation of metal

following high dose

irradiation [M. Rubel, trans.

On fus. Sci. and tech. 53 (2008)

459]


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Calculated thermomechanical effects

D. Garoz et al. Nucl. Fusion 56 (2016) 126014


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Temperature enhancement at a W FW

• In Demo he peak temperature during pulse is near the melting temperature.

• Energy fluence is above reported threshold damage values cracks appear and

propagate shortly after the beginning of operation.



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Temperature enhancement at a W FW

• The FW expands until the irradiation ceases and the material cools down, leading to a tensile state due to the appearance of a plastic region which, affects the first microns of the FW.

• Fatigue appears due to the cyclic nature of the irradiation.

• The lifetime of the FW in the different HiPER scenarios is limited by fatigue loading(Prototype 580 d., Demo 28 h)



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Crack propagation

• Thickness of the W FW is dictated by crack propagation.

• We estimate that a W FW with a thickness of at least ~200 μm.

• Such a thin FW can be fabricated by affordable coating methods offering different

joining possibilities..


KI~5 MPa m1/2 at T~300 K

KI ~10 MPa m1/2 T>300 K


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Conclusions

• Fatigue limit the life time of the FW

– Prototype 580 days

– Demo 28 h

• But….. For Demo a He fluence of 4x 1015 cm-2 is

reached in times of the order of minutes

Development of highly

radiation resistant materials


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Atomistic effects: nanostructured materials

G. Ackland, Science 327, 1587 (2010)


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Nanostructured materials


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PFM: damage and H

• Study the radiation-induced damage and H behaviour

as a function of:

– Sample morphology → NW and CGW

– Implantations conditions:

• Single implantation :H (170 KeV@RT)

• Sequential implantation: C (665KeV@RT) plus H (170KeV@RT)

• Simultaneous implantation: C (665KeV@RT) and H

(170KeV@RT)

• Implantations were selected to mimic as much as

possible IFE conditions


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OKMC: Methodology


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Radiation-induced damage

SRIM MMonCa

G. Valles et al. Acta Mater. 122 (2017) 277–286


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H depth profiles

G. Valles et al. Acta Mater. 122 (2017) 277–286


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H accomodation


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Most stable structures

C. Guerrero et al. J Mater Sci (2015) DOI 10.1007/s10853-015-9464-4


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C. Guerrero et al. J Mater Sci (2015) DOI 10.1007/s10853-015-9464-4

Binding energies


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Charge analysis: Mulliken population

• Maximum electronic interaction occurs between the H and the W 1NNs-Vac for

NH ≤ 6.

• For NH>7, the repulsion between the two H atoms located at the same face of the

primitive cell is stronger, increasing with the number of H atoms in the vacancy.


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Thermomechanical behaviour

•How does temperature affect nanostructured materials?

•Isothermal annealing in vacuum from 298 to 1473 K

•Pulsed thermal loads (PF-400J located at CCHEN)

•Irradiation effects as a function of:•Heat Flux parameter (H)

•Number of shots C0 [nF] 880

L0 [nH] 38

E [J] 345

Vop [kV] 28

Imáx [kA] 127

T/4 [ns] 315

ra [mm] 6

zeff [mm] 7


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H=25 MJm-2s- 1/2(DT=12000 K)

1μm

1μm

1μm

H=1.6 MJm-2s-1/2 (DT=700 K)

H=0.5 MJm-2s-0.5

1μm1μm

Pristine20μm 10μm

10μm 1μm

H=0.5 MJm-2s-1/2 (DT=200 K)

H=7 MJm-2s-1/2 (DT=2000 K)

3μm

Thermal loads effects on NW:

H dependence


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H=25 MJm-2s-1/2 (DT=1200 K)

1μm

1μm

H=0.5 MJm-2s-1/2 (DT=20 K)

1μm

1μm

1μm

pristine

H=1.6 MJm-2s-1/2 (DT=70 K)

Thermal loads effects on CGW: H dependence


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1μm

• NW may exhibit a higher radiation resistance than CGW.

• NW samples may not withstand large thermal loads

(H≥0.5 MJm-2s-1/2)

New approaches needed to design a PFM able to

fulfill specifications

Conclusions


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Upsala GlacierNanostructured W film

IFN MATERIALS GROUP

Prof. José Manuel Perlado

Dra. Emma del Río

Dra. Raquel Gonzalez-Arrabal

Dr. Antonio Rivera

Dr. Ovidio Peña

Pablo DiazNuñez

Pablo diaz

Miguel Panizo-Laiz

José Antonio Santiago Varela

materials development for ife systems documents/ife/20… · second research coordination meeting...

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