Structural Changes in Surface Layers of Vanadium Induced by the Separate and Sequential Impact of Helium Ions and Pulsed Laser Radiation

Autor: V. V. Paramonova, G G Bondarenko, A. I. Gaidar, E. E. Kazilin, I. V. Borovitskaya, S. N. Korshunov, A. N. Mansurova
Rok vydání: 2021
Předmět:
Zdroj: Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 15:332-336
ISSN: 1819-7094
1027-4510
Popis: Changes in the morphology of the vanadium surface are studied as a result of the separate and sequential action of helium ions (for an energy of 30 keV, a dose of 1.0 × 1022 m–2, an ion-flux density of 4.8 × 1018 m–2 s –1, and a temperature of ~500 K) and high-power pulsed laser radiation in the Q-switched mode (power density of q = 1.2 × 1012 W/m2, pulse duration of τ0 = 50 ns, and a pulse number N varying from 1 to 4). It is found that the effect of laser irradiation on vanadium samples before and after ion implantation (resulting in the formation of a crater with a rim due to the splashing of melted metal) is identical. In the case of the preliminary introduction of helium into the material the splash of metal is more intense. Helium implanted into the samples causes radiation blistering; the subsequent influence of laser pulses intensifies material erosion in the area located immediately behind the rim (resulting in a growing number of peeled layers, merging blisters, etc.), which is probably triggered by high temperatures and thermal stresses emerging in this area (even after discontinuing laser irradiation). Under reactor operating conditions this effect can lead to increased plasma contamination. It is shown that the damage of a target inside the craters in the initial vanadium samples feature occasional cracks, wavy and droplet structures, as well as beading, whereas along with the above changes the samples pre-irradiated with helium contain no cracks inside the crater although areas showing boiling of the material are clearly visible.
Databáze: OpenAIRE
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