Study On The Atmospheric Pressure Large Scale Cold Plasma Jet Discharge Characteristics

In recent years, as an emerging discharge technology atmospheric pressure cold plasma jet became a hot topic in the international field of plasma science and technology. The early atmospheric pressure non-equilibrium plasma, mostly the discharge gap is small that limit the shape and size of the workpiece to be treated in the parallel plate electrode. The discharge stability is also susceptible influence. Atmospheric pressure cold plasma jet is a kind of typical non-equilibrium discharge technology, compared to traditional discharge technology, advantages of atmospheric pressure plasma jet is the spatial separation plasma generation region and application zone. Besides, cold plasma jets maintain a strong chemical activity in low gas temperature. At the same time, atmospheric pressure cold plasma jet is a unique technical advantages, has the good controllability, simple operation, low cost, low energy consumption etc. Therefore, in recent years, their desirable properties have made them good prospects, not only in the surface modification of materials, but also in the emerging biomedical, genetic engineering, environmental engineering and the future of information technology development.At present, people have obtained glow-like plasma discharge at small spatial with using a variety of discharge devices and gas. In order to realize the large-scale application of cold plasma jet, the following work is done in this paper:1. Using large scale discharge device, we study the effects of various discharge parameters on the formation of self-organized patterns. The experiment results show that the number of stable discharge channel formation the average discharge current, power consumption increases with the increase of the voltage. The final discharge is filamentary discharge mode. It was also found that the same length of orifice as the discharge device, the smaller of the width the more easily clear of the discharge channel is formed, and the greater of the width the more obvious of the channel glow background. With the increase in the spacing of the discharge, the first discharge inwardly, and the final discharge channel is formed in the middle. The conductivity of the water has great influence on the pattern stability.2. The electrical and optical properties of the organization pattern. We analyze active material composition of plasma jet by acquisition emission spectrum. We make further research by combining electrical signal and the synchronous ultrarapid imaging to observe the evolution of the pattern, which is desirable effect to further study the formation mechanism of self-organization pattern in plasma jets from the microscopic view aspect. The channel of discharge is formed at the same time. Four plasma channels propagate at the speed of about103-104m/s in the air. It must be emphasized that all patterns reappear in the same spatial locations over many thousands of cycles of the applied ac voltage.3. Finally, glow-like plasma discharge of the large scale is studied, with electrical and optical diagnosis. The active species and plasma temperature of the jet in space are consistent. The discharge has good uniformity that has an important influence on the actual industrial application.