由裸露金属电极结构发生器产生的大气压射频辉光放电（Radio Frequency Atmospheric Pressure Glow Discharge，简称RF APGD）等离子体射流具有活性粒子浓度高、射流温度较低且可控性强等特点，在等离子体应用于材料加工及改性、食品工程、环境工程、生物医学等领域得到广泛的应用。本论文以RF APGD等离子体工业微生物诱变育种为研究背景，以高纯氦为工作气体对RF APGD的放电区和射流区特性进行了系统的数值模拟研究，并同实验测量结果进行了定性比较，取得了一些新的、重要的研究进展。 本论文采用流体模型，分别对RF APGD放电区和射流区进行了一维非稳态和二维准稳态数值模拟，研究了发生器几何结构、工作气体流量、电极表面温度及放电电流密度对等离子体特性的影响规律。数值模拟研究结果表明：等离子体放电区主要的能量传递途径为：电源→电子→重粒子→外界环境；随着放电电流密度的增加，放电区活性粒子浓度和气体温度均显著升高，但射流区不同位置处活性粒子数密度并非单调变化；电极表面温度的升高会导致放电区和射流区气体温度的显著升高，但活性粒子浓度变化不大；等离子体工作气体流量的增大会导致放电区气体温度的降低和射流区气体温度的非单调变化，但对活性粒子浓度的影响较小；同轴型发生器非对称的电极结构会导致放电区等离子体参数（如粒子数密度、电子/气体温度及电位分布等）的非对称分布。 基于对等离子体中能量传递过程的分析，本论文提出了在一定程度上对等离子体气体温度和活性粒子浓度进行独立调控的低温气冷型RF APGD等离子体发生器设计理念，通过对发生器电极和工作气体进行冷却的同时提高放电电流密度，获得了气体温度在-7~25 ℃、电子数密度在1015~1016 m-3的等离子体射流。上述数值模拟结果同实验测量得到的放电电压、气体温度等数据定性一致。 另外，本论文尝试将RF APGD等离子体射流应用于甲烷氧化菌诱变育种，获得了具有良好遗传稳定性的突变菌株，从而说明RF APGD等离子体射流是一种高效的微生物诱变育种工具。

Radio frequency atmospheric pressure glow discharge (RF APGD) plasmas with a bare-metallic electrode configuration would have wide applications in the fields of plasma materials processing and modifications, environmental engineering, food engineering, biomedical science, etc., due to their unique features, such as high concentrations of chemically reactive species, low and controllable gas temperatures, and so on. In this thesis, the discharge features and the plasma jet characteristics of the high-purity helium RF APGDs are studied numerically, and are also compared to the experimental measurements with the plasma gene mutation breeding of the industrial microbes as the research background. Some new and important results are presented. In this thesis, the influences of the geometrical configurations of the plasma generators, the working gas flow rates, the surface temperatures of the electrodes and the discharge current densities on the characteristics of the plasmas in the discharge region and jet region are studied using the one-dimensional transient and the two-dimensional quasi-steady fluid models, respectively. The modeling results show that: (i) The energy transfer route in the gas discharge plasmas is “power supply⇒electrons⇒heavy species⇒environment”. (ii) The concentrations of chemically reactive species and gas temperatures in the discharge region increase with increasing the discharge current density, while the variations of species concentrations in the plasma jet region are not monotonous with the current density. (iii) The increase of the electrode surface temperature leads to the obvious increase of the gas temperatures both in the discharge region and in the jet region, while its influences on the species concentrations are very small. (iv) The higher plasma working gas flow rate leads to the decrease of the gas temperature in the discharge region, and a non-monotonous variations in the plasma jet region; while its influence on the species concentrations is negligible. (v) The asymmetric features of the time-averaged plasma parameters, e.g., the species number densities, electron, gas temperatures and the electric field, appear resulting from the increase in the discrepancy between the surface areas of the inner and outer electrodes for a co-axial-type plasma generator. Based on the analysis of the energy transfer mechanisms in the plasma system, a new idea on the design of the RF APGD plasma generator is proposed, with which the gas temperatures and the species concentratios can, to some extent, be adjusted by cooling the generator electrodes and the plasma working gas, as well as by simultaneously increasing the discharge current density. Using the newly designed plasma generator, the plasma jet with the gas temperatures ranging from -7 to 25 ℃ and with the electron number density of 1015~1016 m-3 are obtained. The preceding modeling results are qualitatively consistent with the experimentally measured discharge voltages and the gas temperatures. In addition, the helium RF APGD plasma jet is employed for the gene mutation breeding of M. trichosporium OB3b as one of its applications. The experimental results show that the mutants with high stability can be obtained after treated by the plasma jet, which proves that the RF APGD plasma source is an efficient tool for the genome mutation of microorganisms.