On the Use of Glow‐Discharge Optical Emission Spectrometry for Analysis of Plasma‐Facing Materials

Hydrogen is an element that can easily diffuse into metallic materials. This phenomenon is enhanced at elevated temperature. Diffusion of hydrogen causes alteration of properties of metallic material, e.g., causing hydrogen embrittlement, changing element diffusion by channeling, or decreasing oxide scale adherence due to formation of volatile species. Therefore, understanding hydrogen diffusion processes is of high importance. Thus, in the present article, the changes in the hydrogen distribution in depth are investigated using glow discharge optical emission spectroscopy (GD‐OES). In this work, stainless steel, pure W, and pure Ti were electrochemically charged with hydrogen or deuterium and immediately measured by GD‐OES. Some of the samples were heat‐treated after charging to investigate hydrogen/deuterium diffusion processes. The obtained results showed that variations in the electrolytical charging time cause differences in hydrogenation depths; however, the hydrogen‐rich zone is rather thin. GD‐OES depth profiles of heat‐treated samples clearly showed that the hydrogen and deuterium diffuse outward from the material. This phenomenon causes difficulties in tracing hydrogen after processes at high temperature. Nevertheless, the results obtained showed that GD‐OES is a very useful tool for the investigation of hydrogen and deuterium.