Berlin 2014 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 23: Low Temperature Plasmas II

P 23.2: Vortrag

Donnerstag, 20. März 2014, 14:30–14:45, SPA HS201

Investigation of barrier discharges in He/N₂ mixtures: correlation of electrical, spectroscopic and surface charge measurements — •Robert Tschiersch, Marc Bogaczyk, and Hans-Erich Wagner — Institut für Physik, Ernst-Moritz-Arndt Universität, Felix-Hausdorffstr. 6, 17489 Greifswald

The comprehensive understanding of barrier discharges (BDs) requires identical conditions for the investigation of both volume processes as well as plasma-wall interactions. Hence, the spatio-temporally and spectrally resolved discharge emission and the phase-resolved surface charge accumulation on a BSO crystal were simultaneously studied using the electrically triggered cross-correlation spectroscopy and the electro-optic Pockels effect, respectively. He/N₂ mixtures are suitable for generating the diffuse mode (Townsend-like, glow-like) as well as filamentary-like microdischarges (MDs), simply varying the gas mixing ratio, the amplitude and shape of the applied voltage. The discharge emission evolution and the discharge current show a temporal correlation for direct and multistage excitation. Moreover, comparing the transferred charge during a breakdown with the total amount of deposited surface charges reveals a clear agreement. After switching off the discharge, a decay of the surface charges is observed. Their life-time significantly depends on the illumination rate due to the photoconductivity of the BSO crystal.
Supported by “Deutsche Forschungsgemeinschaft, Sonderforschungsbereich SFB TR24”.