Influence of argon and helium irradiation on structure of multilayer iron-berylium systems

The processes of radiation damage in thin foils of iron and iron with one-side and two-sided beryllium coatings after irradiating by ions of helium and argon are investigated. The technique of beryllium coatings on alpha-Fe production was follow. The specimens have been made of the alpha-Fe foils (enriched by 57Fe isotope up to 89 at. %), rolled to the thickness ∼10 (am and subject to homogenization annealing in vacuum at 800 deg. C for 2 hours. The deposition of Be onto the iron foil have been carried out by magnetron sputtering. The thickness of deposited beryllium layer on the one side of specimen was varied from 0.27 to 2.1 μm. In experiments also were studied of a foil with two-sided beryllium coating, thus the beryllium layers was deposited on both sides of a foil by magnetron sputtering technique. The thickness of deposited beryllium layer on the one and second side of specimen was approximately ∼1.3 μm. In two-side beryllium covered specimens where prepared thermal stable distribution of Fe-Be phase trough thickness of specimens using thermal treatment. Samples of pure alpha-iron and alpha-iron with one-side and two-sided beryllium coatings was subjected to irradiation by alpha particles and argon ions on accelerator 'Wezuvii' (Kazakhstan Institute of Nuclear Physics) for research of radiation resistance: stability of the phase structure, formation gas bubbles etc. Irradiation conditions were the following: Energy of irradiating particles from 330 to 350 keV; Total dose: 3·1016 to 1·1017 particles/cm2, Temperature of irradiation: less than 100 deg C.; The structure of irradiated and after irradiated annealed specimen was studied by conversion electrons Moessbauer spectroscopy technique (CEMS), X-ray, Rutherford back scattering method (RBS), optical microscopy (OM) and scanning electron microscopy (SEM) technique. It is shown that the irradiation by alpha particles of two-sided beryllium coated iron foils at room temperatures up to dose 3·1016 particles/cm2 does not result in destruction of thermal stable distribution of Fe-Be phase trough thickness of specimens. The distribution of concentration of beryllium trough specimen depth in alpha-iron foil with one-side beryllium coating after irradiation by argon ions with energy 350 kV looks like close to distribution of implanted argon. Concentration of beryllium is maximal (∼35 at. %) at distance of 300 nm from the irradiated surface and is decreased practically up to zero at surface and at distance of 1000 nm from the surface