Study of Nanostructured Layer Growth on Plasma-Facing Materials Irradiated with Helium Plasma

Abstract

Tungsten and stainless steel samples were irradiated with stationary helium plasma in the plasma linear multicusp plasma device. The surface of the material is modified under the influence of helium plasma with the formation of nanostructures and microstructures on the surface. The fluence of helium ions equal to 8 × 10²⁷ ions/m² was achieved on the tungsten sample. Depending on the helium ion fluence, fuzzlike layers, loops, and bubbles of 20- to 500-nm scale were formed on the tungsten surface. The fuzz layer thickness depends on the duration of plasma irradiation in a wide range of fluence. Saturation of the growth of the thickness of the tungsten fuzz layer was observed at a fluence of more than 8 × 10²⁶ ions/m². The growth of microstructures and nanostructures on the surface of stainless steel irradiated with helium plasma was observed. The growth of nanostructured layers is explained by a theoretical model considering the dynamics of adatoms under the influence of plasma.

Keywords:

• Helium plasma
• nanostructures
• metals
• tungsten
• stainless steel

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Plasma experiments on the PLM device were supported by Russian Science Foundation grant [number 21-79-10281]. Material analyses were supported by the Ministry of Science and Higher Education of the Russian Federation FSWF-2023-0016 and state assignment [number 075-00270-24-00].