Spatial and temporal studies of plasmas generated with a fast-pulsed DBD

Abstract

Dielectric barrier discharges (DBDs) produce highly nonequilibrium plasmas that allow for the effective generation of ions, excited species, and radicals from energetic electron- driven processes. DBDs have further proven to be efficient sources of intensive UV and VUV excimer radiation. In an effort to improve the production of the excited species, radicals, and UV radiation, which is strongly influenced by the reduced electric field, it is more effective to use a pulsed high voltage of very short duration, particularly if the aim is to keep the gas temperature low. Operating with short pulses and high reduced electric fields will transfer most of the electron energy into excitation, ionization, and molecular dissociation, while only a minor part into the vibrational and rotational excitation of gas molecules. In an effort to better understand this phenomenon, electrical measurements in conjunction with plasma emission spectroscopy and optical imagining studies of a pulsed DBD were carried out using a fast intensified CCD (ICCD) camera. These investigations allowed for the determination of the temporal and spatial developments of important plasma species such as radicals (OH, NO, and various oxygen radicals) along with the determination of the involved microplasma phenomena.