Theory And Experiments Of High-Pressure Glow Discharge

High-pressure glow discharge has many applications such as surface modification, thin film deposition, detoxification of gaseous pollution, plasma display panel, UV excimer lamps and UV excimer laser. In the thesis, a few novel high-pressure glow discharges such as micro-hollow cathode discharge (MHCD), plane cathode micro-hollow anode discharge, plane cathode micro-hollow anode sustained glow discharge are systematically investigated. The electrical and optical properties of these discharges for their potential applications are discussed.MHCD has many outstanding properties as a high-pressure glow discharge. A plane cathode micro-hollow anode discharge is given based on the configuration of MHCD. The discharge can also operate stably at high-pressure. In order to generate large-volume glow discharges at high-pressure, compared to MCSD, plane cathode micro-hollow anode sustained discharge is put forward. The discharge is also stable high-pressure glow discharge. Self-consistent fluid model is presented for MHCD and plane cathode micro-hollow anode sustained discharge. The mean electron energy distribution function (EEDF), electron density, mean electron energy (electron temperature), excitation, and ionization rates have been calculated. The results show that their EEDF is non-Maxwellian distribution, with a high-energy electron tail. The EEDF profile moves toward right with increasing pressure, so the high-energy electrons will increase. In MHCD, in per unit volume, the excitation and ionization rates are positive proportional to the cube of the gas pressure. The electron density is positive proportional to the square of the gas pressure. In plane cathode micro-hollow anode sustained discharge, the peak value of EEDF will move toward right when the third electrode voltage increases with constant current and gas pressure, but it will reach a saturated value. The spatial electron distribution is in agreement with the experiment results. Moreover, the spatial electron distribution will shrink with gas pressure increasing.In order to satisfy the requirement of the high-pressure discharge experiments, a portable high-voltage soft-switching power supply is devoloped. The reliable control circuit and modulation circuit are designed. The experimental results indicate that the power supply operates in resonant condition and realizes the zero current or zero voltage switching. The configuration is simple, the operation mode is flexible and the modulation is convenience. The experiments of two-peculiar high-pressure glow discharges are performed in detail. The electrical and the optical measurements show that the discharge has intense ionization and produces intense radiation. The V-I characteristic has a positive slope. The discharge can operate in parallel to form the large discharge array without individual ballasting resistors. In order to make clear and understand the parameter nature of the high-pressure glow discharge plasma, by the spectroscopic diagnostic technique, the plasma parameters are measured. Some valuable parameters are obtained. The discharges are especially conducive to the formation of excimer. The experiment results show that it has the potential of the fabrication direct current excimer. A novel discharge device for the laser is designed. Under high-pressure condition, the electrical properties and the optical properties are investigated. Some better conclusions are obtained. There are high power density and electron density in discharge plasma. The electron density is estimated at 1013cm-3. The device is favor to enhance the gas ionization rate. The experiment results show that the device is appropriate for the micro-laserIn order to optimize the design of the resonator cavity in the high-pressure discharge gas laser, an Eigenvector Method (EM) for calculation of optical resonator modes and beam propagation is brought forward. The merits of EM includes that the considerably simpler procedure of solution of eigenvectors of the matrix eigen-equation replaces the complicated iteration in traditional methods, and there is no dependence on the initial field distribution, and a number of modes can be derived once and the discrimination capability of the resonator can be evaluated easily. The examples using EM to simulate empty resonator cavity and resonator cavity with media are given, and the calculated results match well with other method. EM can also be used to optimize the design of laser resonator cavity.Finally, these micro-discharges for several applications including plasma display panel, film deposition and high-pressure gas conversion are discussed. Some preliminary experiments performed on plasma display penal are presented. Some excellent capabilities are shown. The application areas of the high-pressure glow discharge are constantly exploited.