Integrated Modeling of Helium-Vacancy Clustering in Eurofer97 Steel Upon He+/Fe3+ Dual Ion Beam Irradiation

Here, by developing an integrated rate theory model, we studied helium-vacancy (He-V) clustering in ferritic/martensitic steel Eurofer97 under He + /Fe 3+ dual ion beam irradiation condition. Different from the known single peak concentration profile of total atomic He, the ‘solute’ He atom (interstitial He) concentration displays a bimodal distribution during irradiation due to the kick-out mechanism aided by irradiation-induced self-interstitials. We show that the kicked-out interstitial He enhances the He-V clustering rate and leads to the shift of cluster pressurization states. The He-V clustering direction is also governed by the kicked-out interstitial He.