Erlangen 2018 – scientific programme
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P: Fachverband Plasmaphysik
P 9: Atmospheric Pressure Plasmas II
P 9.3: Talk
Tuesday, March 6, 2018, 14:45–15:00, A 0.112
Experimental investigation of microdischarges in a needle-to-hemisphere dielectric barrier discharge in air at atmospheric pressure — •Sina Jahanbakhsh1, Volker Brüser1, and Ronny Brandenburg1,2 — 1INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald — 2Institut für Physik, Universität Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock
Metal pin-to-dielectric coated electrode arrangement, known as barrier corona (BC), offers synergies between corona discharge (low breakdown voltage) and Dielectric barrier discharge (DBD) (charge limitation). In this study a sharp metal pin (0.2 mm tip radius) and a hemispherical (2 mm radius) alumina covered electrode are employed. A sinusoidal voltage at the frequency of 7.5 KHz is applied at 11.5 kVp-p. Using an ICCD camera and a Rogowski coil current probe, pictures and current pulses of individual MDs are recorded simultaneously. Time correlated single photon counting (TC-SPC) is used to record the spatio-temporal development of the MDs. The discharge inception and the MD properties in the two polarities of the sinusoidal voltage differ significantly. This contribution will focus on the results of the negative polarity (dielectric cathode). In this polarity two groups of MDs are observed in the same half-period. The first MD leaves a positive surface charge on the dielectric. This residual charge has considerable effects on the propagation and properties of the second MD, such as longer fall and rise time of the current pulse, and longer propagation on the surface of the dielectric.