Enhancement of Retention and Features of Deuterium Detrapping from Radiation- Induced Damage in Steels

Full text of publication follows: There is significant interest for fusion reactor materials on the well understanding of the interaction between displacement damage and co-generated helium and hydrogen, because of sufficient synergistic effect of this species on their mutual behaviour in materials. The influence of pre-implanted helium and heavy ions induced damage on deuterium trapping in austenitic, ferritic/martensitic steels was studied using thermal desorption spectrometry, the nuclear reactions 3He(D,p)4He and D(3He,p)4He, and transmission electron microscopy. Deuterium retention and release were studied for 10 keV D2+ and 10 keV He+ implantation at room temperature followed by annealing from 300 to 1500 K. Energetic heavy ions irradiation (Ar+) has been used for modeling of defect cluster formation and microstructural evolution under displacement cascade condition so as to simulate fusion reactor environments. As a first approximation the data on evolution of the distribution profiles of damage produced in monocrystal Ni under irradiation by Ar+ ions (E = 0.2...1 MeV) in the dose range 1.1019...1.1021 m-2 obtained by means of channeling are used for modeling of damage profiles development in construction alloys. The amounts of trapped and released deuterium and helium atoms were measured as a function of implantation dose at various temperatures. It was found that retention of hydrogen and deuterium is strongly enhanced by the presence of helium (especially at large He amounts) and also strongly enhanced by damage introduced by 1.4 MeV Ar+ ions. (authors)