Radiation damage of material surfaces under prolonged irradiation with He+ and Ar+ ions with broad energy spectra

The results of studying the redistribution of Be, Al, Ti, Fe, Cu, Zr, Mo, and W atoms incorporated in polycrystalline metal samples under irradiation with He+, (He+ + Ar+), and Ar+ ion beams with a broad energy spectrum and an average energy of 10 keV at irradiation doses of 1 × 1021 ion/cm2 are studied. It is discovered that irradiation at doses exceeding 1 × 1019 ion/cm2 results in local small-crystal formations being produced in a near-surface substrate layer. Their typical dimensions are less than 1–5 μm, and their the density is up to 1–100. They contain incorporated atoms and impurity atoms with a concentration of 0.1–10 at %. Subsequent irradiation at a dose of 1 × 1020 ions/cm2 or more leads to disappearance of these formations, mainly because of sputtering processes.