Hannover 2010 – scientific programme
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P: Fachverband Plasmaphysik
P 21: Poster: Plasma-Wall Interaction
P 21.1: Poster
Monday, March 8, 2010, 16:00–18:00, Lichthof
De-excitation of metastable nitrogen molecules on surfaces - Quantum kinetic modeling — •Johannes Marbach, Franz Xaver Bronold, and Holger Fehske — Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany
Secondary electrons emitted from plasma boundaries are generally very important for the operation of a gas discharge. There is for instance experimental evidence that the stability of the diffusive mode of dielectric barrier discharges is controlled by seed electrons at the electrodes [1]. However, up to now it is not clear how these electrons are made available on the microscopic scale. One possibility is the de-excitation of metastables at the boundary with subsequent release of electrons. To model this intrinsic non-equilibrium process we employ the Keldysh Green’s function technique which in principle enables us to calculate the de-excitation probability of the metastable molecules as well as the number of electrons emitted from the surface. As a preparatory step we investigate the de-excitation of metastable nitrogen A3Σu+ molecules impacting on an ideal aluminium surface. For this special situation there is detailled experimental and theoretical data available which we use to validate our methodology.
[1] R. Brandenburg, V. A. Maiorov, Yu. B. Golubovskii, H.-E. Wagner, J. Behnke and J. F. Behnke, Diffuse barrier discharges in nitrogen with small admixtures of oxygen: discharge mechanism and transition to the filamentary regime. J. Phys. D: Appl. Phys., 38:2187, 2005