Spectroscopic characterization of a He/N₂ dielectric barrier discharge for determination of plasma parameters and estimation of impurity content

ORAL

Abstract

Optical emission spectroscopy (OES) is among the most convenient methods for plasma diagnostics, as it allows to investigate a plasma without physical intervention. In this study, absolutely calibrated optical emission spectroscopy is used together with a collisional radiative model to determine the electron density, reduced electric field and gas temperature in a low temperature volume dielectric barrier discharge (vDBD) in helium with small admixtures of nitrogen. The vDBD is operated in an enclosed chamber at atmospheric pressure to control all necessary environmental conditions. Nevertheless, nitrogen emission is observed even without intentional addition to the chamber. To better understand the discharge properties, OES is also used to estimate the air impurity content in the chamber. A fitting procedure is used to separate overlapping emission bands and estimate the gas temperature. The ratio of the fitted N₂(C-B) and N₂⁺(B-X) emission is then used to calculate the reduced electric field. Using the absolute emission intensity, the electron density is then calculated. Calculated electron densities and the impurity of the setup are found to be in the range of 1x10⁹ - 1x10¹⁰ cm⁻³ and ~750ppm, respectively.

*funded by the Deutsche Forschungsgemeinschaft (DFG, #430219886 - PlasNOW)

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Presenters

  • Niklas Nawrath

    • Ruhr University Bochum

Authors

  • Niklas Nawrath

    • Ruhr University Bochum

  • Gregor Welling

    • Ruhr University Bochum

  • Nikita Bibinov

    • Ruhr University Bochum

  • Peter Awakowicz

    • Institute of Electrical Engineering and Plasma Technology, Ruhr University Bochum.
    • Institute for Electrical Engineering and Plasma Technology, Ruhr University Bochum, Germany
    • Institute of Electrical Engineering and Plasma Technology, Faculty of Electrical Engineering and Information Sciences, Ruhr University Bochum, Bochum, Germany.
    • Ruhr Univ Bochum
    • Ruhr University Bochum

  • Andrew R Gibson

    • Research Group for Biomedical Plasma Technology, Faculty of Electrical Engineering and Information Sciences, Ruhr University Bochum, Bochum, Germany.
    • 1) Research Group for Biomedical Plasma Technology, Ruhr-Universität Bochum, Germany; 2) Institute for Electrical Engineering and Plasma Technology, Ruhr-Universität Bochum, Germ
    • Research Group for Biomedical Plasma Technology, Ruhr-University Bochum, Universitätsstraße 150 D-44801 Bo­chum, Germany
    • Ruhr University Bochum, Germany
    • Institute of Electrical Engineering and Plasma Technology, Faculty of Electrical Engineering and Information Technology, Ruhr-University Bochum, Germany
    • Ruhr University Bochum