Effects of energetic particle irradiation on low-activation Fe-base alloys are of important concern for the use of the materials as structural components in advanced nuclear power systems such as fusion DEMO reactors. In the present work irradiation experiment of some ferritic alloys with high-energy Ne ions was carried out to study the effects of atomic displacement: damage and nuclear transmutation gases like helium on the microstructures and the mechanical properties. Specimens of a ferritic alloy (9%Cr) and a ODS al- Effects of energetic particle irradiation on low-activation Fe-base alloys are of important concern for the use of the materials as structural components in advanced nuclear power systems such as fusion DEMO reactors. In the present work irradiation experiment of some ferritic alloys with high- energy Ne ions was carried out to study the effects of atomic displacement: damage and nuclear transmutation gases like helium on the microstructures and the mechanical properties. Specimens of a ferritic alloy (9% Cr) and a ODS al-