Influence of excitation pulse duration of dielectric barrier discharges on biomedical applications

Two dielectric barrier discharges created in atmospheric pressure air were compared to investigate influences of excitation pulse duration on plasma parameters. A plasma source with a pulsed excitation and pulse durations in the mu s range as well as a source with pulse durations in the ns range were investigated. An aluminum plate with skin lipids of the stratum corneum on the one hand and an aluminum needle without lipids for operating in the single filamentary mode on the other hand were used as opposite electrodes. The optical emission spectroscopy was arranged to determine the rotational and vibrational temperatures by comparing experimental with simulated spectra. Vibrational temperatures were calculated in a range 2200-2600 K, rotational temperatures were measured from 300 up to 600 K. In addition, the electron temperatures (7-15 eV) and the reduced electric fields (280-800 Td) were estimated. Electric parameters were detected by both current and voltage measurements with a resulting range 200-500 mW of dissipated power.