**3.2 He implantation**

Acquiring knowledge concerning fusion transmutation product (He and H) effects on structural materials is difficult to study because of the lack of proper facilities. Using an ion beam accelerator, nuclear fusion-related amount of He was incorporated into the structural material, EUROFER97, using two different ways in terms of beam configuration—defocused beam and raster beam. This is a critical matter to consider because different defect evolution has been detected depending on which method has been taken into consideration to perform the irradiations [32, 33].
