Positron annihilation studies of Eurofer97/ODS steels after helium ion implantation. (March 2023)

• Record Type: Journal Article
• Authors: Slugen, Vladimir; Veternikova, Jana Simeg; Degmova, Jarmila; Sojak, Stanislav; Petriska, Martin; Noga, Pavol; Krsjak, Vladimir
• Is Part Of: Nuclear materials and energy. Volume 34(2023)
• Publication Date: 2023-03
• Subjects: Eurofer -- Radiation-induced defects -- Ion implantation -- Slow positron beam -- Positron lifetime -- Doppler broadening -- Nanoindentation; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2023.101369
• Languages: English
• ISSNs: 2352-1791

Abstract

Highlights: Radiation environments foreseen for these materials were experimentally simulated via ion implantation by He + ions (energy 500 keV and fluence 10 22 m −2 ). New vacancy defects in the most radiation-affected zone of Eurofer and ODS Eurofer are located near chromium atoms. ODS Eurofer indicated lower radiation sensitivity than Eurofer in both measurements by slow positron beam. Helium bubbles diameters are visible bigger for Eurofer (with a maximum at about 2 nm), while in the case of ODS, the overage diameter is near to 1.5 nm. Abstract: The paper briefly reviews our positron annihilation studies performed on Eurofer97 steel and its ODS variant, performed in the last about 20 years. Various aspects of radiation environments foreseen for these materials were experimentally simulated via ion implantation and studied by a combination of non-destructive characterization techniques. The primary characterization tools in these studies were two techniques based on positron annihilation, namely positron annihilation lifetime spectroscopy (PALS) and Coincidence Doppler Broadening (CDB) technique. In addition to bulk studies utilizing conventional radioisotope positron sources, ion-implanted specimens were analysed using slow positron beams. This review summarizes the key findings of these techniques concerning the nature of the radiation resistance of EUROFER/ODS steels.