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The enhancement of plasma generation in atmospheric pressure dielectric barrier discharge (DBD) is gaining increasing interest for various plasma applications. In this paper, the effect of surface charges moving with the rotating dielectric plate on improving the generation of streamer channels is investigated by a statistical analysis of electrical measurements, optical diagnostics, and numerical simulation in a needle-plate DBD device with a rotating dielectric plate. Results suggest that rotating the dielectric plate can improve the spatiotemporal distribution of streamer channels by inducing a bending of the streamer channels and an increase in the number of discharges. Statistical results show that the number of current pulse and discharge energy are increased by 20% and 47%, respectively, at the rotating speed of 160 rps (revolution per second). Based on the interaction between the applied electric field and the electric field induced by surface charges, a formula is proposed to govern the effect of rotating the dielectric plate on the discharge energy and streamer bending. To further understand the mechanism of the influence of rotating the dielectric plate on plasma properties, a 2D fluid model is implemented, and the reduced electric field and streamer propagation are analyzed. Results show that the effective transfer and reuse of surface charges play an important role in the enhancement of plasma generation. [ABSTRACT FROM AUTHOR]

Enhancing discharge energy in dielectric barrier discharge (DBD) is vital for various applications. This study establishes a theoretical formula for predicting enhanced discharge in multi‐needle‐plate (MP) DBD, accounting for factors like needle count, rotation speed, and voltage frequency. Experiments validate the formula's accuracy, showing that precisely matched parameters result in enhanced discharge power, heightened streamer luminosity, and curved streamer channels. Lissajous figures in MP DBD exhibit elliptical shapes due to residual discharges during voltage fall. Statistical analysis of current pulses and discharge images confirms that dielectric plate rotation increases discharges and extends their duration during voltage fall. Numerical simulations highlight surface charge movement's role in enhancing the electric field and affecting streamer propagation direction in the air gap. [ABSTRACT FROM AUTHOR]

We present the triangular lattice pattern with the invisible Kagome lattice in the dielectric barrier discharge system with two water electrodes for the first time. The spatio-temporal dynamics studied by an intensified charge-coupled device (ICCD) show that the complex pattern is composed of four different sublattices: Kagome lattice, halos, and big and small spots (B and S). The invisible Kagome lattice is similar to the dark discharge because of its spatio-temporal randomness. Based on the novel discharges (B and S) occurring at the falling edge of applied voltage, the dynamics of surface charges is investigated and demonstrated with a high speed video camera and photomultiplier tubes. Furthermore, the formation of restricted random structures is considered to be the effect of previous discharges which rearrange the surface charges. [ABSTRACT FROM AUTHOR]

We report a square superlattice pattern with discharge holes due to direction-selective surface discharges (SDs) in a dielectric barrier discharge system for the first time. The instantaneous images with an exposure time of 10 μs (half cycle of voltage) taken using a high-speed video camera show that the directions of surface discharges (SDs) of the small spots are selective, which are different from the directions of SDs of the large spots diffused in all directions. In each positive half cycle of voltage, the graphs captured using an intensified charge-coupled device show that the large spot discharges after the small spots and locates at the center of the square formed by the SDs induced by small spots but not their cross point. In each negative half cycle of voltage, the large spots discharge before the small spot and press the SD of the small spot to stretch along the midperpendicular of two adjacent large spots. In a word, the direction-selective surface discharges play a crucial role for the formation of the pattern with the discharge holes in the dielectric barrier discharge system. [ABSTRACT FROM AUTHOR]

We report on a novel dielectric barrier discharge (DBD) instrument with asymmetrical electrodes. It consists of three water electrodes, one big electrode faces to two small electrodes placed side by side, any one of two small electrodes connects with a high-voltage diode which can control on or off of applied power. Using this DBD experimental setup, the phenomenon of forming two kinds of different patterns at the different parts of discharge gap simultaneously is investigated for the first time. The spatio-temporal characteristic of these different patterns limited by the boundary which contains two connected same circles is studied. It is shown that although the power source is applied on one part of the discharge gap at a half period because of existence of high voltage photodiode, the discharge occurs at both areas in each half period of the applied voltage. Results have prospective applications for studying the discharge mechanism and different characteristic of positive and negative charges in forming of pattern. [ABSTRACT FROM AUTHOR]