Darmstadt 2008 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P IV: Poster: Niedertemperaturplasmen II, Astrophysikalische Plasmen, Magnetischer Einschluss, Plasma-Wand-Wechselwirkung

P IV.17: Poster

Donnerstag, 13. März 2008, 16:00–18:30, Poster C2

Studying Breakdown in Xenon-Model-Discharge Lamps — •Michael Schmidt¹, Martin Wendt¹, Silke Peters¹, Manfred Kettlitz¹, Andreas Kloss², and Hartmut Schneidenbach¹ — ¹Leibniz-Institute of Plasma Science and Technology, Felix-Hausdorff-Straße 2, D-17489 Greifswald — ²Osram-GmbH, Hellabrunner Straße 1, D-81536 München

Studying the breakdown phase in a simplified lamp geometry can contribute to the understanding of the ignition of high-intensity-discharge (HID)-lamps. Therefore, the volume breakdown between two tip electrodes was studied at Xenon pressures up to 5× 10⁵ Pa. A camera system of four independent ICCDs pictured the spatio-temporal evolution of single streamers. The influence of statistics was reduced by UV-illumination of the lamp tubes. Different power circuits provided voltage ramps dU/dt of 5 MVs⁻¹ up to 10 GVs⁻¹, while breakdown voltage and current were measured by electrical probes. With rising dU/dt the breakdown voltage increased independently on pressure. This trend was reproduced using a 1d-model, developed by Ebert et al. [1], in combination with an outer electrical circuit. At lower pressures a lower breakdown voltage was measured, while the streamer’s diameters increased as observed for other electrode systems, like a tip-plate geometry [2].

[1] U. Ebert et al., Phys. Rev. E 55 (1997), 1530