Aachen PK 2003 – wissenschaftliches Programm
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PV: Plenarvorträge
PV VIII
PV VIII: Plenarvortrag
Mittwoch, 19. März 2003, 14:00–14:45, FO1
Progress in the diagnostics of filamentary gas discharges at atmospheric pressure — •Hans-Erich Wagner — Institute of Physics, University of Greifswald, Domstr. 10a, D-17489 Greifswald, Germany
Filamentary gas discharges at atmospheric pressure (barrier discharges, coronas) produce highly non-equilibrium plasmas in a controllable way at moderate gas temperature. They provide the effective generation of atoms, radicals and excited species by energetic electrons. Consequently, they have found a large field of applications. Their experimental investigation and the measurement of plasma parameters requires a sub-ns temporal and sub-mm spatial resolution. Efforts on these fields are reviewed. Recently, the technique of spatially resolved cross-correlation spectroscopy (CCS) has been used to contribute to a better understanding of these discharge types. The interest is focused on barrier discharges operating in air and nitrogen / oxygen mixtures. Quantitative estimates for electric field strength E(x,t) in air and for relative electron density ne(x,t)/nmax are derived from the experimentally determined spatio-temporal distributions of the luminosity for the spectral bands of the 0−0 transitions of the second positive system of N2 (λ=337.1 nm) and the first negative system of N2+ (λ=391.5 nm). The influence of the spatio-temporal structure of the discharge on the chemical kinetics of ozone synthesis is studied, too. Additionally, first investigations on coronas are presented.