2023, Harutyunyan, Z., Gasparyan, Y., Efimov, V., Krat, S., Umerenkova, A., Арутюнян, Зорий Робертович, Гаспарян, Юрий Микаэлович, Ефимов, Виталий Сергеевич, Крат, Степан Андреевич, Умеренкова, Анастасия Сергеевна

Helium (He) isotope exchange in tungsten (W) during sequential irradiation by 3 keV 4He and 3He ions at room (RT) and elevated temperatures (700-1200 K) was investigated. The total He fluence was in the range of 5 × 1021–1.8 × 1022 He/m2 to provide a saturation of the surface layer. The amount of He retained in W after irradiation was measured using in-situ (up to 1500 K) and ex-situ (up to 2500 K) thermal desorption spectroscopy (TDS). Air exposure influenced TDS spectra, but clear were no noticeable differences between 3He and 4He TDS spectra after single irradiation. Subsequent irradiation with different He isotopes demonstrated a very efficient isotope exchange already at room temperature. The substitution of He atoms goes even faster with increasing irradiation temperature. Mechanisms of observed processes are discussed on the base of a simple model. © 2022