Characteristics of free-radical in a magnetized sheet plasma crossed with vertical gas-flow -production and quantitative mesurment-

自由基在等离子体与中性气体分子的反应机制中起着重要的作用，这主要是由于其优异的物理和化学性质。我们提出了一种新设计的磁化片状等离子体系统与垂直气流交叉的系统。该系统的几何形状用等离子体厚度表示，估计接近一维（1-D）。影响自由基和等离子体的参数，如反应气体流速、等离子体密度和电子温度，通过选择实验条件很容易控制。利用激光诱导荧光（LIF）、光分离法和电探针分析了气体和等离子体之间的接触现象。LIF光谱是一种检测自由基的高灵敏度方法。因此，在与垂直气流交叉的磁化片状等离子体系统中，可以实现基于简单模型的自由基定量分析。本文研究了氩气磁化片状等离子体与O_2-H_2混合气体垂直流动交叉时羟基自由基数密度的测定。OH自由基是研究最多的燃烧种类，也是环境研究的重要种类。此外，我们还演示了在与O_2气体垂直气流交叉的氩气磁化片状等离子体中O^-和O^-_数密度的测量。这些负离子是等离子体处理和环境研究的重要种类。我们的结果可以用于确定负离子产生的最佳条件，以及解释与各种等离子体参数有关的中性气体分子与等离子体碰撞的复杂现象。

Free radicals play an important role in reaction mechanisms between plasma and neutral gas molecules mainly because of their outstanding physical and chemical properties. We have proposed a newly designed system of a magnetized sheet plasma system crossed with a vertical gas-flow. The geometry of this system expressed in th scale of plpasma thickness is estimated to be nearly onedimensional (1-D). Parameters affecting the free radicals and the plasma, such as reactive gas flow rate, plasma density, and electron temperature, are easily controlled by selecting the experimental conditions. Contact phenomena between gas and plasma are analyzed by using laser-induced fluorescence (LIF), a photodetached method and an electrical probe. The LIF spectroscopy is a highly sensitive method for detecting free radicals. Therefore, a quantitative analysis of free radicals based on a simple model can be achieved in the magnetized sheet plasma system crossed with the vertical gas-flow.In this research we studied the measurement of the number density of hydroxyl (OH) free radicals in the magnetized sheet plasma of argon crossed with vertical gas flow mixed of O_2-H_2 gas mixture. The OH free radical is the most commonly studied combustion species and is an important species from the view point of environment studies. Also, we demonstrated the measurement of the number density of O^- and O^-_ in the magnetized sheet plasma of argon crossed with vertical gas flow of O_2 gas. These negative ions are an important species for plasma processing and environment studies. Our results can be useful in determining the optimum conditions for negative ion production as well as in explaining the complex phenomena involved in the collisions between neutral gas molecules and plasma in relation to various plasma parameters.