Review and critical assessment of dislocation loop analyses on EUROFER 97

Highlights: • Data on dislocation loop microstructure after neutron irradiation has been completed. • Available microstructural data on EUROFER 97 is compared; differences in results are assessed and partially explained. • A line-up of dislocation loops at possible dislocation lines is observed. - Abstract: The understanding of microstructural defects behavior after neutron irradiation is crucial for assessing the applicability of reduced activation ferritic/martensitic (RAFM) steel EUROFER 97 in future fusion reactors. Formation and evolution of dislocation loops is believed to play the major role in material's hardening under neutron irradiation. In this work, transmission electron microscopy (TEM) data on dislocation loop size distribution is provided after different irradiation campaigns to determine the role of neutron dose on the dislocation loop evolution. A comparison of investigations on dislocation loop behavior and appearance yield considerable differences. For a conclusive interpretation, this work reviews available data, and possible reasons for the observed differences are discussed. Recommendation for future TEM investigation are given.