Strains in light-ion-implanted polycrystals: influence of grain orientation

The implantation of He ions in UO₂ polycrystals induces a strain in the implanted layer which can be characterized using Laue micro X-ray diffraction (µ-XRD). The strain tensor resulting from the ion implantation may not be reduced to a single out-of-plane strain component: it also has nonzero shear components. Their strong dependence upon crystal orientation is modeled using elasticity theory. This work demonstrates the potential of Laue µ-XRD for characterizing radiation effects in materials.