An In-situ TEM Investigation of Silicon Carbide under Irradiation
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Transcript of An In-situ TEM Investigation of Silicon Carbide under Irradiation
An In-situ TEM Investigation of Silicon Carbide under Irradiation
Chris PawleyUniversity of Salford
UNTF 2011, 11-13 April 2011, University of Huddersfield
University of SalfordMaterials & Physics Research Centre
http://www.cse.salford.ac.uk/sumc/
M-F. Beaufort & J-F. BarbotUniversity of Poitiers
E. OlivieroCSNSM, Orsay, Paris
S.E. Donnelly & J.A.HinksUniversity of Huddersfield
University of SalfordMaterials & Physics Research Centre
Outline• Where SiC fits into the nuclear industry
• Aim of our research
• Facilities utilised during the research
• Results obtained
• Understanding the results and feedback into a nuclear context
University of SalfordMaterials & Physics Research Centre
Putting SiC into a nuclear context• Why is it good as a nuclear material?
– Radiation Hardness– Chemically inert– High temperature stability
• Expected conditions– Operating temperature between 550°c and
1000°c– 10,000 appm– 150 DPA
University of SalfordMaterials & Physics Research Centre
Example applications of SiCCurrent• TRISO coatings
Future• First wall material for fusion
reactors
[1] E.Lopez-Honorato et al, (2009) TRISO coated fuel particles with enhanced SiC properties, Journal of Nuclear Materials, Vol 392 Issue 2, Page 219-224 [2]A.Serpo,(2008) Nuclear fusion becomes economic reality? accessed 10/04/2011 http://www.zdnet.com.au/nuclear-fusion-becomes-economic-reality-339285739.htm
TRISO coated particle 1
Tokomak design employed at ITER 2
University of SalfordMaterials & Physics Research Centre
Aim of the Project• Understand nucleation and growth
processes of He bubbles in SiC
• Learn about the behaviour of SiC (and the He bubbles within) under high energy, heavy ion irradiation
• Feed into nuclear design considerations for the future
University of SalfordMaterials & Physics Research Centre
In-Situ Radiation Facilities• MIAMI facility at Salford
– Upto 100keV ions into JEOL 2000fx TEM
• JANNuS facility at Orsay, Paris– Upto 2MV ions into FEI Technai G2 20.
University of SalfordMaterials & Physics Research Centre
Results
• MIAMI facility– 3.5keV He+ ions– 2.7x1013 ions.cm-2.s-1
– End point: 2.0x1017 ions.cm-2
• Aim: Observe nucleation & growth
University of SalfordMaterials & Physics Research Centre
Results• JANNuS facility
– 2MeV Au++ ions– 3x1011 ions.cm-2.s-1
– End point: 2.5x1015 ions.cm-2
• Aim: Observe behaviour under displacing irradiation
University of SalfordMaterials & Physics Research Centre
Interpretation of resultsBubble observations• Growth is inhibited during 2nd
irradiation step– Thermal and irradiation processes
competing
• SRIM supports this
University of SalfordMaterials & Physics Research Centre
Interpretation of resultsSurface observations• Reconfiguration due to sputtering
• Sputtering yield from SRIM supports this as a possibility
• Reduction in hermetic efficiency of SiC– Could change the context in which silicon carbide
is utilised in future nuclear applications
• Essential to interpret this for the neutron case
University of SalfordMaterials & Physics Research Centre
Conclusions• Bubble growth in SiC is inhibited by
displacing irradiation.– Changes to the depth profile of helium within
SiC
• Significant surface change occurs towards the high end of the temperature range together with irradiation. – Changes the hermetic efficiency of SiC in
nuclear type applications
University of SalfordMaterials & Physics Research Centre
Acknowledgements• EPSRC
– Financing the development of the MIAMI facilityunder grant number EP/E017266/1
• Royal Society– Financing travel to JANNuS under an international
joint project with University of Poitiers
• University of Salford– For the provision of a graduate teaching assistant
position which supports this research
• University of Huddersfield– For hosting UNTF 2011 and for providing a new
home to the MIAMI facility