Direct Comparison of Tungsten Nanoparticles and Foils under Helium Irradiation at High Temperatures Studied via In-Situ Transmission Electron Microscopy

The nanoengineering of materials for enhanced radiation damage tolerance by increasing the density of defect sinks and recombination centres has been investigated in nanograined, nanolayered, nanoporous, and nanodispersion-strengthened materials. For example, in a nanoporous material an interconnected network of ligaments forms a structure in which the surface-area-to-volume ratio, RSV, is high and the distance to the nearest surface is always short. These surfaces act as insaturable sinks at which defects can annihilate and mobile gas atoms escape. This is particularly important in nuclear materials where neutron irradiation can induce the creation of vacancies and interstitials via atomic displacements as well as the introduction of insoluble gases such as helium from (n,α) reactions.