| As microplasma generated in the form of plasma jet,atmospheric pressure low temperature microplasma jet can be generated under driven of direct current,alternating current,radio frequency and microwave sources.Compared with common size atmoepheric pressure low temperature plasma jet,atmospheric pressure low temperature microplasma jet is able to possess higher thermal stability and reactive species production,and it can be used to treat object with smaller surface area such as a single cell directly and naturally has a higher degree of integration on a unit area.However,as its size decreases,atmospheric pressure low temperature microplasma jet is becoming more and moer difficult to be generated.In this thesis,we focus on the research gap of atmospheric pressure low temperature microplasma jet in the size of 10?m and below 10?m,and choose four kinds of dielectric tubes,for each of which we design a corresponding discharge device.In those tubes,atmospheric pressure low temperature microplasma jets with the sizes of 10?m,6?m,3.4?m and changing size with a minimum of 10?m are generated respectively,and corresponding electrical and optical diagnostics methods are occupied to diagnose each of the generated atmospheric pressure low temperature microplasma jets.The main content of this thesis is as below:First,by designing a corresponding discharge device,an atmospheric pressure low temperature He microplasma jet with a length of2.5cm is generated in the dielectric tube with an inner diameter of 10?m,and its aspect ratio reaches2500.Benefited from the high specific surface area of the dielectric tube,the gas temperature of the He microplasma jet is only around 600K which is obtained from N2 C3??-B3?g???=-2?spectra analysis.The electron density of the He microplasma jet is high up to1.3×1016cm-3,which is obtianed from Stark broadening of H?spectrum.Second,based on the research discussed above,by designing a corresponding discharge device,an atmospheric pressure low temperature Ar microplasma jet with a length of3cm is generated in the dielectric tube with an inner diameter of 6?m,and its aspect ratio reaches5000,which is further improved when compared with the He microplasma jet in the 10?m dielectric tube.Benefited from the high specific surface area of the dielectric tube,the gas temperature of the Ar microplasma jet is only about 480K,which is obtained from N2 C3??-B3?g???=0?spectra analysis.The electron temperature of the Ar microplasma jet is found to be1.5eV by using the collisional-radiation model,and the electron density of the Ar microplasma jet is high up to3.6×1016cm-3,which is obtianed from the Stark broadening ofAr2p2?1s5spectrum.Third,based on the research discussed above,by designing a corresponding discharge device,an atmospheric pressure low temperature Ar microplasma jet array,of which the length is2cm and the size of the single jet is 3.4?m,is generated in the multi porous photonic crystal fiber whose single hole is 3.4?m in diameter.The aspect ratio of the Ar microplasma jet array reaches5880,which is further improved when compared with the Ar microplasma jet in the 6?m dielectric tube.Benefited from the high specific surface area of the dielectric tube,the gas temperature of the Ar microplasma jet array is only around 500K,which is obtained from N2 C3??-B3?g???=0?spectra analysis.The electron temperature of the Ar microplasma jet is found to be0.85eV by using the collisional-radiation model,and the electron density of the Ar microplasma jet is high up to8.7×1016cm-3,which is obtianed from the Stark broadening ofAr2p2?1s5spectrum.Fourth,based on the research discussed above,by designing a corresponding discharge device,an atmospheric pressure low temperature He microplasma jet is generated in the dielectric tube whose inner diameter decreases from 245?m to 6?m.The He microplasma jet has a length of 1.5cm and its minimum size researches 10?m.The gas temperature at different position of the He microplasma jet is obtained from N2C3??-B3?g???=0?spectra analysis,and the gas temperature first increases as the position departs from the high voltage electrode and then gradually retain540K.The enlarged view of the He microplasma jet indicates that the He microplasma jet does't fill the cross section of the dielectric tube until the inner diameter of dielectric tube is below 30?m.The electron density at different position of the He microplasma jet is obtianed from Stark broadening of H?spectrum,and it increases as the inner diameter of the dielectric tube decreases.Based on the relationship between elctron density and inner diameter of the dielectric tube,we forcast that if He microplasma jet were finally generated in a 1?m tube,the electron density would reach an order of 1018cm-3.In research,we also obtain the relationship between the ignition voltage and the inner diameter of the dielectric tube,and based on that we forcast that in order to get He microplasma jet in 1?m tube,voltage up to65kV should be provided.In summary,we realize atmospheric pressure low temperature microplsma jets with the size of 10?m,6?m and 3.4?m and forcast the atmospheric pressure low temperature microplsma jet with the size of 1?m in this work.All of them can serve as references and provide data support for future simulation and experiment research. |
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