The use of in-situ ion-irradiation/TEM techniques to study radiation damage in SiC

SiC is a material currently under consideration to be used in future generations of fission and fusion reactors where it will be subjected to high temperatures and significant fluxes of energetic neutrons. The work reported in this thesis aims to answer some outstanding issues of the behaviour of SiC at high temperature during irradiation by high-energy neutrons in combination with a build-up of helium (from both transmutation reactions and by direct implantation). These processes have been simulated by in-situ ion-irradiation / TEM at the MIAMI and JANNuS facilities.This thesis contains the results of experiments which investigated the nucleation and growth of helium bubbles in SiC and the behaviour of these helium bubbles under high energy heavy ion-irradiation. Our conclusions are that helium bubbles in SiC are extremely stable at high temperatures and during high-energy ion-irradiation. However, we have discovered that there is a significant effect on the bubbles attributable to either electron beam irradiation alone or the synergistic effect of the electron beam and ionirradiation which causes helium bubbles to shrink