Bremen 2017 – scientific programme

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P: Fachverband Plasmaphysik

P 8: Plasma Diagnostics II

P 8.5: Talk

Tuesday, March 14, 2017, 09:50–10:05, HS 1010

Electric field measurement in diffuse helium-nitrogen barrier discharge by Stark polarization spectroscopy — •Sebastian Nemschokmichal, Robert Tschiersch, and Jürgen Meichsner — Institute of Physics, Ernst-Moritz-Arndt-University of Greifswald

Discharges in helium with molecular admixtures like nitrogen or oxygen are important for applications at atmospheric pressure because of their ability to produce radicals at low power requirements. For a better understanding of these discharges and to optimize applications, numerical simulations and their comparison with crucial discharge parameters of the experiment are necessary. One important discharge parameter is the electric field strength, which can be determined by Stark polarization spectroscopy at 492.2 nm and from the intensity ratio of the two singlet lines at 667.8 nm and 728.1 nm [1]. The combination of both methods allows a precise absolute calibration by the Stark polarization spectroscopy and a good spatial and temporal resolution by the intensity ratio method. For this contribution, these methods are applied to a diffuse dielectric barrier discharge driven by a square wave voltage in helium with 500 ppm nitrogen admixture at a gap distance of 3 mm. In contrast to previous investigations of such discharges, a photomultiplier is used instead of an ICCD camera to improve the temporal resolution and to avoid the blurring by the jitter in discharge breakdown. In addition, it is planned to compare the spatio-temporally resolved electric field strength with 1D fluid simulations.

[1] Ivković et al. J. Phys. D: Appl. Phys. 47 (2014) 055204