Microstructural evolution and thermo-mechanical behaviour of fine-grain graphite materials

High energy particle physics experiments such as LBNE at Fermilab require the production and study of neutrinos. Fine-grained graphite materials have been selected as neutrino production target materials that have been constantly irradiated by high power, high energy and intensified proton beams operating cyclically with short pulse period (340KW, 120GeV, 1.1mm beam sigma and microseconds pulse time). Therefore, the irradiation behaviours of these nano crystalline graphite with complex multiple-length scale microstructures (nano to macro) depict their useful lifetime and performance for being proton irradiation target and neutrino yields. The multiple-length scale microstructures of graphite control their micro- and bulk thermo-mechanical properties and as such, a multi-length scale characterisation and experimental mechanics methodology must be adopted for a comprehensive understanding of target graphite's proton irradiation behaviour to be acquired. This project will be mainly employing micro-Raman spectroscopy, micro X-ray tomography (microXCT), Focused ion beam scanning electron microscopy (FIB-SEM), neutron diffraction, X-ray diffraction, small angle X-ray scattering (SAXS), digital volume/image correlation and various (micro-) mechanical testing methods (in situ and/or ex situ) to examine unirradiated and unirradiated fine-grained target graphite materials as well as several other counterparts popular in the nuclear graphite industry. Expecting a comprehensive and sound mechanistic understanding of these representatives of modern fine-grained nuclear graphite could be obtained through this PhD project, validating their reliability in various physical/engineering applications including next generation fission reactor systems (molten salt and HTGRs) and accelerator-driven facilities around the world.