https://doi.org/10.1140/epjd/e2013-40279-x
Regular Article
Influence of the applied voltage shape on the barrier discharge operation modes in helium
1 Institute of Physics,
Ernst-Moritz-Arndt University, Felix-Hausdorff-Str. 6, 17489
Greifswald,
Germany
2 Faculty of Physics, University of
Belgrade, Studentski trg
12, 11000
Belgrade,
Serbia
a
e-mail: bogaczyk@uni-greifswald.de
Received:
2
May
2013
Received in final form:
30
July
2013
Published online:
18
October
2013
For the investigation of a barrier discharge (BD) operated in helium, a discharge cell configuration was used which allows an electrical characterization and simultaneous measurements of volume processes as well as the interaction of the BD with a dielectric surface. The emission development in the volume has been recorded spatio-temporally and spectrally resolved by the established cross-correlation spectroscopy (CCS) operating in the PPG mode. The phase resolved measurement (over one discharge period) of surface charges deposited on a BSO crystal was realized by the utilization of the electro-optic Pockels effect in combination with a high-speed camera. Depending on the gap distance, the dielectrics, and the shape of feeding voltage, the BD can operate either in the diffuse Townsend-like or glow-like mode. The emission is localized near the anode and cathode for the Townsend-like mode and glow-like mode, respectively. In small gaps (distance about 1 mm), a sinusoidal feeding voltage leads to the unusual Townsend-like mode in helium. But, a square wave voltage shape induces the glow-like mode, probably due to the fast rise and fall time of the applied voltage slopes. A sawtooth voltage generates both discharge modes over one period. The presented results show clearly the correlation of the emission development with electrical measurements, and deposited surface charge and transported charges.
Key words: Plasma Physics
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2013