A study of the porosity of nuclear graphite using small-angle neutron scattering
Mileeva, Z, Ross, DK and King, SM 2013, 'A study of the porosity of nuclear graphite using small-angle neutron scattering' , Carbon, 64 , pp. 20-26.
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Small angle neutron scattering (SANS) measures porosity in nuclear graphites, including both open pores, caused by escaping decomposition gases, and internal cracks (in coke particles) generated by anisotropic thermal contraction along the c-direction (Mrozowski Cracks). Porosity changes on the length scale observable by SANS must control the development of internal stresses and hence of cracking in AGR graphite due to irradiation (both fast neutron displacements of carbon atoms and radiolytic corrosion by CO2). Such cracking may cause premature reactor shutdown. SANS measurements show that porosity is fractal on a length scale between ~0.2-300 nm, presumably due to Mrozowski cracks – because the fractal index of the SANS signal depends only on the porosity of the graphitic filler. We report here two novel uses of the SANS technique as applied to reactor graphite – contrast matching with D-toluene (to measure the fraction of the porosity open to the surface) and the temperature dependence of the scattering (to measure pore width changes up to 2000 °C). These results provide important new information on AGR graphite porosity and its evolution during irradiation.
|Uncontrolled Keywords:||nuclear graphite, irradiation damage, small angle neutron scattering|
|Schools:||Schools > School of Computing, Science and Engineering
Schools > School of Computing, Science and Engineering > Salford Innovation Research Centre (SIRC)
|Journal or Publication Title:||Carbon|
|Funders:||Engineering and Physical Sciences Research Council (EPSRC)|
|Depositing User:||Prof D. Keith Ross|
|Date Deposited:||20 Jun 2013 16:31|
|Last Modified:||30 Nov 2015 23:54|
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