Affiliation:
1. National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., 077125 Magurele, Romania
2. Doctoral School of Physics, Faculty of Physics, University of Bucharest, 405 Atomistilor Str., 077125 Magurele, Romania
Abstract
We show that in plasmas generated in deuterium in the presence of sputtered W surfaces, various molecular tungsten species are formed, whose chemical composition depends on the presence of gaseous impurities, namely, nitrogen, oxygen, and hydrogen. A magnetron discharge was used for plasma sustaining, and the species were investigated by mass spectrometry and optical emission spectroscopy. The identified tungsten-containing molecules are described by the chemical formula WOxNyDzHt, where x = 0–4, y = 0–3, z = 0–3, t = 0–5. Presumptively, even higher mass tungsten molecular species are present in plasma, which were not detected because of the limitation of the spectrometer measurement range to 300 amu. The presence of these molecules will likely impact the W particle balance and dust formation mechanisms in fusion plasmas.
Funder
European Union through the EUROfusion consortium and the Romanian Ministry of Research, Innovation and Digitalization
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