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P: Fachverband Plasmaphysik
P 12: Magnetic Confinement / Plasma Wall Interaction I
P 12.6: Talk
Wednesday, March 30, 2022, 15:15–15:30, P-H12
Application of a spatially resolved emission model to sputtered tungsten atoms at the linear plasma device PSI-2 — •Marc Sackers, Oleksandr Marchuk, Stephan Ertmer, Philippe Mertens, Arkadi Kreter, and Sebastijan Brezinsek — Forschungszentrum Jülich GmbH - Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Deutschland
Highly charged atomic species in the core of a fusion plasma are detrimental to the successful operation of the reactor because they lead to significant cooling of the plasma due to radiation losses. For example, at ITER, the divertor will consist of tungsten blocks [1]. The main erosion channel of these blocks is physical sputtering, which needs to be understood at a fundamental level to estimate tungsten concentration in the plasma core for different operating scenarios.
In this work, the PSI-2 plasma-surface interaction test-bed provides divertor-like conditions. Its plasma source is an arc discharge between a hollow ring-shaped cathode and anode. This geometry allows the acquisition of high-resolution emission spectra (λ/Δλ≈7·105) for lines of sight parallel and perpendicular to the surface normal of a target exposed to the plasma. A spatially resolved emission model was fitted to spectra of the 498.26 nm neutral tungsten line obtained during sputtering of mono- and polycrystalline tungsten targets. The angular and energy distribution were derived for bombardment with argon ions from 40 eV to 160 eV.
[1] R.A. Pitts et al., J. Nucl. Mater. 2011, 415, S957-S964