Study On The Atmospheric Pressure Large Scale Cold Plasma Jet

Cold plasma jets generated in atmospheric pressure discharges represent a rapidly developing technology of great application promises. With the hybrid effects of gas flow and electric field, the regions of plasma generation and application are separated, which makes the plasma less influenced by the downstream sample. Their properties, including low temperature, high reactive chemical species, easy dynamic control and simplicity of operation etc, have made them unique and promising for a number of important industrial applications, such as biomedical engineering, environmental engineering, plasma chemistry, and material processing etc. Since the properties of plasma play a key role for the industrial applications and scientific researches, it is of great importance to optimize the performance of atmospheric pressure cold plasma jets, especially to improve the uniformity, stability and effective area. The following work is done in this paper:1. An atmospheric pressure nonequilibrium Ar/O2 plasma jet assisted by the preionization of syringe needle electrode discharge is carried out. The application of an auxiliary preionization discharge is capable to provide high enough density of seed electrons prior to the discharge, which makes the electron avalanches liable to overlap each other and coalesce in lower electric field, thus glow discharge mode can be produced with lower breakdown voltage, low temperature, and high atomic oxygen concentration can be obtained. Utilizing the actinometry method, the concentration of atomic oxygen is measured, which is about 1016cm3. The Ar/O2 plasma jet is employed to clean out the heat transfer oil and a maximum cleaning rate of 0.1 mm/s had been obtained.2. A further study on the self-organized patterns in an atmospheric pressure dielectric barrier discharge (DBD) plasma jet is carried out based on the previous work. The influences of experimental conditions on the mode transition are investigated, and the reason for the pattern formation is discussed. Besides the applied voltage and the gas flow rate, we find the frequency of power and the scales of generator also play a vital role in the evolvement of the self-organized pattern. The results demonstrate that an increase of the scale of the jet generator and/or the discharge frequency is shown to enlarge the number of discharge channels.3. The experiment of atmospheric pressure cold plasma jet array is carrying out. A series of jet arrays (arranged in 3 jet array,7 jet array and 13 jet array) with the basic structure of equilateral triangle are investigated, in which a ring-plate cold atmospheric jet is used as the element component. The results demonstrate that the jet array is applicable to produce low temperature, homogeneous and larger area plasma stability. The jet array provides possible method to further study of scalable plasma jet array.