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

自由基由于其优异的物理化学性质，在等离子体与中性气体分子的反应机理中起着重要的作用。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。用等离子体厚度尺度表示的系统几何形状估计接近一维。影响自由基和等离子体的参数，如反应气体流量，等离子体密度和电子温度，很容易通过选择实验条件进行控制。利用激光诱导荧光（LIF）、光剥离法和电探针分析了气体与等离子体之间的接触现象。激光诱导荧光光谱是一种高灵敏度的自由基检测方法。本文研究了垂直气流与氩气混合的磁化等离子体中羟基自由基数密度的测量。OH自由基是最常被研究的燃烧物种，从环境研究的角度来看是一个重要的物种。此外，我们还测量了在氩气的磁化等离子体中，O^-和O^-的数密度。这些负离子是等离子体处理和环境研究的重要物种。我们的结果可以是有用的，在确定负离子产生的最佳条件，以及在解释复杂的现象，涉及中性气体分子和等离子体之间的碰撞与各种等离子体参数。

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.