Excitation dynamics of a kHz driven micro-structured plasma channel device operated in argon

The excitation dynamics of a micro-structured plasma channel device with an inverted equilateral triangular cross-section are investigated. This device is operated in argon close to atmospheric pressure with an ac voltage. It is characterized by means of electrical measurements and optical emission spectroscopy. One emission phase is observed in each half-cycle of the applied voltage waveform. Each shows self-pulsing of the device. The integrated intensities for both phases differ by a factor of about two. Phase-resolved wavelength-integrated optical emission spectroscopy which resolves the intensity profile of the plasma channel reveals clear differences between positive and negative half period. Emission features propagating along the discharge channel at velocities of a few km s-1 are observed. Discharge dynamics are compared with those reported for micro-structured atmospheric pressure plasma arrays with discharge cavities of similar triangular cross-section. The comparison allows conclusions on the interaction of individual inverted pyramidal cavities.