基于OH基团二级光谱的氩大气压等离子体射流温度诊断

Diagnosis of Temperature for Argon Atmospheric Pressure Plasma Jets with Oxyhydrogen Grating Secondary Spectrum

为了应用OH基团的二级光谱来诊断大气压等离子体射流(APPJs)的温度,首先采用线性场电极结构产生了氩大气压等离子体射流,利用增强型电荷耦合器件(ICCD)和三光栅光谱仪,拍摄了200～900nm波长范围内氩APPJs的光谱,并对光谱进行了辨认及分析,结果表明,除了氩原子的2p-1s(帕邢符号)跃迁谱线外,还存在一些分子基团的一级和二级光栅光谱,且其二级光谱的分辨率远高于一级光谱,其中OH(其相应跃迁为A2∑+→X2П)自由基尤为明显。然后选择OH(A2∑+→X2П)自由基的二级光谱诊断了OH自由基的转动温度(近似为等离子体射流的温度),并探讨了该温度随外施电压幅值、气体体积流量的变化,结果表明,在其他实验条件(如管径、电极间距和电极宽度)给定的情况下,氩APPJs的温度随外施电压幅值和气体体积流量的增大而都呈现先下降后上升的趋势,当外施电压幅值为10kV、气体体积流量为4L/min时,温度达到最小值348K。上述结果将为氩AP-PJs的参数调节及应用提供重要的帮助。

In order to use the secondary grating spectrum to diagnose the temperature of atmospheric pressure plasma jets （APPJs）, the open condition APPJs in argon are given first by linear field electrodes configuration. Intensified charge coupled device （ICCD） and three-grating spectrometer are used to capture plasmas spectra range from 200 nm to 900 nm. Then the temperature of plasma jets are further diagnosed by using captured spectra. Identification and analysis for the spectra reveal that the argon atom spectral lines transition 2p--ls （Paschen＇s notes） are present. In addition, the primary and its secondary grating sPectra of some molecular radicals also appear, and resolution of the secondary grating spectrum is far higher than its primary resolution, especially for OH （A2∑＋→X2H） radical. The secondary grating spectra of OH （A2∑＋→X2H） radical are selected for diagnosing temperature of argon APPJs. The trend of the temperature of argon APPJs with applied voltage and gas flow velocity under fixed other conditions （quartz tube diameters, distance between electrodes, and electrodes width） are also investigated. The results indicate that argon APPJs＇ s temperature varying with both above parameters decreases to its minimum of 348 K then increases when the applied voltage is fixed at 10 kV and gas flow are 4 L/min, respectively.