大气压空气等离子体羽的振动温度研究

Vibrational Temperature of Plasma Plume in Atmospheric Pressure Air

利用三电极介质阻挡放电装置,在大气压空气中产生了较大体积的等离子体羽。采用光学方法对该等离子体羽的特性进行了研究。发现随着外加电压峰值增加,每个外加电压周期的放电脉冲个数增加。通过采集等离子体羽的发射光谱,空间分辨地研究了放电等离子体羽的振动温度。结果表明等离子体羽的振动温度随着外加电压峰值的增加而减小;随着远离喷嘴的距离的增加,等离子体振动温度先增加后减小,当距离喷嘴5.4mm时振动温度达到最高值。对上述现象进行了定性分析。研究结果对大气压空气等离子体羽在杀菌消毒等领域的应用具有重要意义。

A tri-electrode discharge device was designed in a dielectric barrier discharge configurations to generate a fairly large volume plasma plume in atmospheric pressure air. The discharge characteristics of the plasma plume were investigated by an op- tical method. The discharge emission from the plasma plume was collected by a photomultiplier tube. It was found that the num- ber of discharge pulse per cycle of the applied voltage increased with increasing the peak value of the applied voltage. The emis- sion spectra of the plasma plume were collected by a spectrometer. The vibrational temperature was calculated by fitting the ex- perimental data to the theoretical one. Results showed that the vibrational temperature of the plasma plume decreases with in- creasing the Up. Spatially resolved measurement of the vibrational temperature was also conducted on the plasma plume with the same method. Results showed that the vibrational temperature increases firstly and then decreases with increasing distance from the nozzle. The vibrational temperature reachs its maximum when the distance is 5.4 mrn from the nozzle. These experimental phenomena were analyzed qualitatively based on the discharge theory. These results have important significance for the industrial applications of the plasma plume in atmospheric pressure air.